UC-NRLF 


- 


UNITED  STATES  DEPARTMENT  0F  AGRICULTURE 
BULLETIN  No.  772 

Contribution  from  the  Bureau  of  Plant  Industry 
WM.  A.  TAYLOR,  Chief 


Washington,  D.  C.  PROFESSIONAL  PAPER 


March  20,  1920 


THE  GENERA  OF  GRASSES  OF  THE 
UNITED  STATES 

WITH  SPECIAL  REFERENCE  TO  THE  ECONOMIC  SPECIES 

By 

A.  S.  HITCHCOCK.  Systematic  Agrostologist 


CONTENTS 


Page 
Scope  and  Plan  of  the  Work    .....       1 

Poaceae,  the  Grass  Family  ......       5 

Descriptions  of  the  Subfamilies  and  Keys 

to  the  Tribes     ..........       6 

Descriptions  of  the  Tribes  and  Keys  to 

the  Genera  ........... 


Descriptions  of  the  Genera 

1.  Bamboseae,  the  Bamboo  Tribe 

2.  Festuceae,  the  Fescue  Tribe     . 

3.  Hordeae,  the  Barley  Tribe  .. 


4.  Aveneae,  the  Oat  Tribe    .....    106 

5.  Agrostideae,  the  Timothy  Tribe   .    .    121 

6.  Nazieae  ^he  Curly-Mesquite  Tribr       165 


Paeg 
Descriptions  of  the  Genera— Continued. 

7.  Chlorideae,  the  Grama  Tribe  ...  171 

8.  Phalarideae,  the  Canary-Grass  Tribe  199 
9:  Oryzeae,  the  Rice  Tribe 204 

10.  Zizanieae,  the  Indian-Rice  Tribe     .  206 

11.  Melinideae,    the    Molasses  -  Grass 

Tribe 212 

12.  Paniceae,  the  Millet  Tribe  .    .    .    .213 

13.  Andropogoneae,  the  Sorghum  Tribe  252 

14.  Tripsaceae,  the  Corn  Tribe ....  280 
List  of  New  Species  and  New  Names  .    .288 
Index 289 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 

1920 


UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 

^^   BULLETIN  No.  772 

Contribution  from  the  Bureau  of  Plant  Industry 
WM.  A.  TAYLOR,  Chief 


Washington,  D.  C. 


PROFESSIONAL  PAPER 


March  20,  1920 


THE  GENERA  OF  GRASSES  OF  THE  UNITED  STATES, 
WITH  SPECIAL  REFERENCE  TO  THE  ECONOMIC 
SPECIES. 

By  A.  S.  HITCHCOCK,  Systematic  Agrostologist. 


CONTENTS. 


Page. 

Scope  and  plan  of  the  work 1 

Poaceae,  the  grass  family 5 

Descriptions  of  the  subfamilies  and  keys  to 

the  tribes 6 

Descriptions  of  the  tribes  and  keys  to  the 

genera 8 

Descriptions  of  the  genera 22 

1.  Bamboscae,  the  bamboo  tribe 22 

2.  Festuceae,  the  fescue  tribe 24 

3.  Hordeae,  the  barley  tribe 87 

4.  Aveneae,  the  oat  tribe 106 

5  Agrostideae,  the  timothy  tribe 121 


Page. 
Descriptions  of  the  genera — Continued. 

6.  Nazieae,  the  curly-mesquite  tribe 1G5 

7.  Chlorideae,  the  grama  tribe 171 

8.  Phalarideae,  the  canary-grass  tribe  ...  1C9 

9.  Oryzeae,  the  rice  tribe 201 

10.  Zizanieae,  the  Indian-rice  tribe 206 

11.  Mclinideae,  the  molasses-grass  tribe  . .  212 

12.  Paniceae,  the  millet  tribe 213 

13.  Andropogoneae,  the  sorghum  tribe...  252 

14.  Tripsaceae,  the  corn  tribe 280 

List  of  new  species  and  new  names 288 

Index ...  289 


SCOPE  AND  PLAN  OF  THE  WORK. 

The  present  bulletin  describes  all  the  genera  of  grasses  that  include 
species  that  are  native,  have  been  introduced,  or  are  cultivated  in  the 
United  States.  Under  each  genus  are  given  the  species  that  are 
of  economic  importance,  either  as  useful  or  harmful  grasses.  Of  all 
grasses  the  grains  are  of  the  greatest  importance.  Chief  among  other 
useful  grasses  are  those  that  are  cultivated  for  meadow  or  pasture 
and  those  indigenous  species  which  furnish  forage  upon  the  native 
pasture  or  ranges.  Other  important  grasses  are  the  sugar-producing 
species,  those  used  in  broom  or  paper  making,  and  the  ornamental 
species. 

It  is  intended  to  give  under  each  genus  the  botanical  information 
concerning  all  our  grasses  that  are  conspicuous  enough  to  have  at- 
tracted the  attention  of  agriculturists.  The  keys  to  the  tribes  and 

97700°— Bull.   772—20 1 


2  BULLETIN   772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 

genera  should  enable-  the  user  to  identify  the  genera  of  all  our  grasses^ 
and  the  text  under  each  genus  should  enable  him  to  determine  the 
species  of  our  economic  grasses.  Under  each  genus  are  given  the 
type  *  and  the  synonyms  based  upon  American  species,  or  the  names 
that  have  been  used  in  an  American  publication. 

The  following  generic  names,  of  which  the  types  have  not  been 
found,  are  based  on  American  material  but  are  unidentifiable  from 
the  descriptions: 

Anthipsimus  Raf.,  Journ.  de  Phys.  89:  105,  1819.2  Based  on  A.  gonopodus 
Raf.,  "  Dry  hills  of  the  Ohio." 

Dactylograrama  Link,  Hort.  Berol.  2 :  248.  1833.  Based  on  D.  cimwides  Link, 
described  from  garden  specimens  grown  from  seed  from  western  North 
America. 

Flexularia  Raf.,  Journ.  de  Phys.  89:  105.  1819.  Based  on  F.  comprcssa  Raf., 
"Kentucky  and  Ohio." 

The  tribes  have  been  arranged  in  a  new  sequence  based  on  the  com- 
plexity of  the  flower  structure,  the  most  primitive  being  placed  first 
and  the  most  highly  developed  last.  It  is  impossible  to  arrange  them 
in  a  lineal  sequence  and  at  the  same  time  represent  their  relationships, 
as  the  phylogenetic  development  has  not  been  along  a  single  line. 
The  present  arrangement  is  the  closest  approximation  to  natural  re- 
lationships that  can  be  shown  in  sequence.  The  highest  development 
in  any  given  tribe  may  be  far  more  complex  than  the  most  primitive 
example  of  the  tribe  placed  above  it,  but  the  relative  development  of 
each  tribe  is  believed  to  be  fairly  represented  by  its  position  in  the 
sequence.  The  bamboos  are  placed  lowest,  as  certain  genera,  such  as 
Arundinaria,  show  the  least  differentiation  in  the  floral  structure. 
The  Andropogoneae  and  Tripsaceae  are  highly  specialized,  as  is 
shown  by  the  great  diversity  and  complexity  of  the  floral  structures. 
The  tribe  Oryzeae  of  most  authors  includes  two  groups  of  diverse 
genera,  each  worthy  of  tribal  rank.  The  allies  of  rice  (Oryza)  are  here 

1  The  type  species  of  a  genus  is  the  species  or  one  of  the  species  the  author  had  chiefly 
in  mind  when  describing  the  genus.     Most  authors  of  to-day  designate  the  type  species, 
but  earlier  authors  usually  did  not.     To  make  the  application  of  generic  names  more  cer- 
tain, old  genera  are  now  put  on  a  type  basis  ;  that  is,  one  of  the  original  species  is  chosen 
as  the  type.     If,  then,  a  genus  as  originally  established  included  species  belonging  in  two 
or  more  genera  the  name  of  the  genus  goes  with  the  type  species  and  the  species  related 
to  it.     It  will  be  seen  that  the  type  species  of  a  genus  as  here  given  often  bears  a  differ- 
ent generic  name.     (See  Miegia,  based  on  Arundinaria  macrosperma,  p.  22,  and  Panicu- 
laria,  based  on  Poa  aquatica,  p.  34.)     This  means  that  the  genus  was  based  on  a  species 
previously  described  under  a  different  genus.     In  this  work  the  type  species  is  given  for  all 
generic  names,  whether  valid  or  synonyms.     The  reasons  for  selecting  a  certain  species  as 
the  type  are  given  in  each  case.     Among  several  species,  the  one  most  familiar  to  the  au- 
thor of  the  genus  may  be  selected  as  the  type.     Species  described  by  Linnaeus  in  his  flora 
of  Sweden  (Flora  Suecica)  and  in  his  flora  of  Lapland  (Flora  Lapponica)   were  familiar 
to  him  and  are  often  the  types  of  his  genera.      (For  a  further  discussion  of  types,  see 
Hitchcock,  Generic  Types  with  Special  Reference  to  the  Grasses  of  the  United  States,  Amer. 
Journ.  Bot.  5 :  248-253,  May,  1918  ;  and  Report  of  the  Committee  on  Generic  Types  of  the 
Botanical  Society  of  America,  Science,  n.  ser.  49:  333-336,  Apr.  4,  1919.) 

2  The  form  for  literature  citations  throughout  this  bulletin  is  in  the  main  that  used 
in  publications  of  the  United  States  National  Herbarium. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  6 

retained  in  the  tribe  Oryzeae,  while  the  allies  of  Indian  rice  (Zizania) 
have  been  segregated  as  the  tribe  Zizanieae.  Several  genera  referred 
to  Oryzeae  in  current  works  on  the  classification  of  the  grasses  but 
not  represented  in  the  United  States  are  evidently  not  closely  allied 
to  either  tribe.  Their  disposition  is  deferred,  pending  further  study. 

The  tribe  Nazieae  (Zoysieae)  also  is  composed  of  diverse  genera. 
Hilaria  and  Aegopogon  should  be  segregated  from  Nazia,  Anthe- 
phora,  and  their  allies.  They  are  more  closely  related  to  certain  of 
the  Chlorideae,  such  as  Bouteloua  and  Cathestecum.  For  the  present- 
they  are  appended  to  the  Nazieae,  as  their  final  disposition  must  await 
a  careful  comparison  with  several  genera  outside  our  geographical 
limits. 

One  species  of  each  genus  is  illustrated.  '  A  few  of  the  larger 
genera  are  represented  by  more  than  one  illustration,  especially  if 
the  habit  of  the  species  shows  considerable  diversity.  The  chief 
figure  of  each  illustration  shows  the  habit  of  the  plant,  and  the  ac- 
cessory figures  show  the  structure  of  the  spikelets  and  florets.  The 
habit  drawings  are  usually  half  natural  size;  the  details  of  the 
spikelet  are  enlarged  from  2  to  20  times.  The  parts  of  the  spikelet 
shown  are  selected  to  indicate  generic  differences  and  are  not  uni- 
formly of  comparable  parts,  though  there  is  always  a  figure  of  a 
spikelet  and  generally  of  a  floret.  The  habit  drawings  are  by  Mary 
Wright  Gill,  and  the  details  of  the  spikelet  are  by  Agnes  Chase. 

There  are  in  the  United  States  about  1,500  species  of  grasses.  Of 
these  about  60  are  cultivated.  Approximately  140  native  species  are 
important  forage  grasses  and  are  constituents  of  our  stock  ranges  or 
of  wild  prairie  hay.  Many  others  are  occasionally  eaten  by  stock 
but  are  not  sufficiently  abundant  to  be  included  among  our  economic 
grasses.  About  60  species  are  wreeds  introduced  from  foreign  coun- 
tries, chiefly  from  Europe. 

In  this  bulletin  the  word  grass  is  used  in  its  botanical  sense,  that 
is,  as  applying  only  to  plants  of  the  natural  family  Poaceae  (or 
Gramineae).  Many  plants  other  than  grasses  are  used  for  forage, 
among  such  the  clovers,  alfalfa,  vetches,  peas,  beans,  and  other 
leguminous  species  being  the  most  important.  Sedges  and  rushes 
resemble  grasses  but  belong  to  distinct  plant  families.  The  rushes 
(Juncaceae)  are  distinguished  by  having  small  green  flowers  with  a 
6-parted  perianth.  The  sedges  (Cyperaceae)  are  distinguished  from 
grasses  by  having  3-rankecl  leaves.  The  stems  are  often  3-sided. 
The  leaves  of  grasses  are  2-ranked  and  the  stems  are  never  3-sided. 
The  flowers  of  sedges  are  small  and  greenish,  like  those  of  grasses, 
but  there  is  no  bract  (palea)  between  the  flower  and  the  rachilla. 
Sedges  and  rushes  usually  inhabit  wet  places  or  marshes, .  though 
some  of  them  (such  as  the  nut-grass,  Cyperus  rotundus}  are  weeds 


4  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

in  cultivated  soil.  They  are  usually  of  little  importance  as  forage 
plants.  The  sedges  and  rushes  are  not  included  in  this  bulletin. 

The  cultivated  grasses  may  be  classified  according  to  their  use  as 
grains,  forage  grasses,  sugar-producing  grasses,  textile  grasses,  soil 
binders,  lawn  grasses,  and  ornamental  grasses. 

Grains  are  those  grasses  whose  fruit  or  grain  is  used  for  food  or 
for  stock  feed.  The  common  grains  are  wheat,  corn,  oats,  rye,  bar- 
ley, rice,  sorghum,  and  millet. 

The  forage  grasses  are  those  used  for  meadows,  pastures',  soiling, 
and  silage. 

Meadow  grasses  are  those  cut  for  hay.  The  chief  meadow  grasses 
of  the  United  States  are  (1)  in  the  cool  humid  region,  timothy,  red- 
top,  orchard  grass,  and  meadow  fescue;  (2)  in  the  warm  humid 
region,  Bermuda  grass,  Johnson  grass,  and  (in  Florida)  Natal  grass: 
(3)  in  the  dry  area  east  of  the  Great  Plains,  millet  and  sorghum 
(including  its  varieties,  such  as  kafir  and  Sudan  grass)  ;  (4)  in 
the  northern  part  of  the  Great  Plains,  brome-grass ;  (5)  on  the  Pa- 
cific coast,  wheat,  oats,  and  barley  for  the  production  of  grain  hay. 

Wild  hay  is  chiefly  from  three  sources:  (1)  Prairie  hay  from  the 
region  lying  just  east  of  the  Great  Plains,  including  various  native 
species  such  as  big  bluestem  (Andropogon  furcatm}*  little  bluestem 
(A.  scoparius),  Indian  grass  (Sorghastrum  nutans),  and  switch- 
grass  (Panicum  virgatum)  ;  (2)  fresh  marsh  hay  from  the  region  be- 
tween the  Dakotas  and  Michigan,  including  chiefly  bluejoint  (Cala- 
magrostis  canadensis) ,  reed  canary  grass  (Phalams  ammdinacea) , 
and  slough-grass  (Beckmannia  erucaeformis)  ;  and  (3)  salt  marsh 
hay  used  mostly  for  bedding  and  for  packing,  including  usually  salt- 
marsh  grass  (Spartina  patens)  and  black-grass  (a  kind  of  rush, 
Juncus  gerardi). 

Pasture  grasses  are  those  that  furnish  forage  to  grazing  animals. 
The  two  most  important  cultivated  pasture  grasses  of  the  United 
States  are  bluegrass  in  the  Northern  States  and  Bermuda  grass  in 
the  South.  The  meadow  grasses  are  also  used  for  pasture,  and  in 
the  Gulf  States  carpet  grass  is  of  some  importance. 

The  wild  grasses  used  for  grazing  are  commonly  called  range 
grasses.  The  most  important  are  (1)  on  the  Great  Plains,  buffalo 
grass,  curly  mesquite,  and  grama  (Bouteloua  grac'dis  and  B.  hirsuta)  ; 
(2)  in  the  Southwest,  several  species  of  grama  (Bouteloua),  Hilaria, 
and  Sporobolus  airoides;  (3)  in  the  mountain  regions,  pine-grass, 
blue  bunch-grass,  and  mountain  bunch-grass  (in  Oregon) ;  Arizona 
fescue  (in  northern  Arizona) ;  and  the  wheat-grasses  (in  the  Rocky 
Mountains). 

Soiling  grasses,  those  cut  and  fed  green,  include  the  common  small 
grains,  corn,  and  the  sorghums,  and  (locally  in  the  South)  pearl 
millet  and  teosinte. 


GENERA   OF   GRASSES   OF   THE    UNITED   STATES.  5 

Any  forage  grass  may  be  preserved  in  a  silo,  but  corn  is  the  one 
most  commonly  used  for  this  purpose. 

The  most  important  lawn  grasses  are  (1)  in  the  North,  bluegrass, 
Rhode  Island  bent,  and  creeping  bent;  (2)  in  the  South,  Bermuda 
grass,  carpet  grass,  and  St.  Augustine  grass. 

The  ornamental  grasses  include  the  reeds,  such  as  pampas  grass 
and  eulalia ;  border  grasses,  such  as  fountain  grass  and  blue  fescue ; 
and  variegated  grasses,  such  as  ribbon  grass. 

Soil-binding  grasses  are  species  having  vigorous  rhizomes  which 
hold  sand  or  other  loose  soil  and  prevent  erosion  by  water  or  wind. 
Banks  are  secured  against  water  erosion  by  a  covering  of  redtop  or 
Bermuda  grass.  The  most  important  sand  binder  in  use  in  this  coun- 
try is  beach-grass  (AimnophUa  arenaria).  This  is  planted  upon 
sand  dunes  to  prevent  wind  erosion. 

The  two  sugar-producing  grasses  are  sugar  cane  and  the  saccha- 
rine varieties  of  sorghum.  No  textile  grasses  are  cultivated  in  the 
United  States.  The  esparto  grasses  (Spartina  tenacissima  and 
Lyyeum  spartum)  of  Spain  and  Algeria  furnish  fiber  for  the 
manufacture  of  paper  and  cordage. 

All  these  grasses  are  mentioned  in  the  text  under  the  proper  genus. 
(See  index.) 

POACEAE,  THE  GRASS  FAMILY. 

Flowers  perfect  (rarely  unisexual),  small,  with  no  distinct  peri- 
anth, arranged  in  spikelets  consisting  of  a  shortened  axis  (rachilla] 
and  2  to  many  2-ranked  bracts,  the  lowest  two  being  empty  (the 
glumes,  rarely  one  or  both  .of  these  obsolete),  the  one  or  more  succeed- 
ing ones  (lemmas]  bearing  in  their  axils  a  single  flower,  and,  between 
the  flower  and  the  rachilla,  a  second  2-nerved  bract  (the  palea),  the 
lemma,  palea,  and  flower  together  constituting  the  floret;  stamens  1 
to  6,  usually  3,  -with  very  delicate  filaments  and  2-celled  anthers; 
pistil  1,  with  a  1-celled  1-ovuled  ovary,  2  (rarely  1  or  3)  styles,  and 
usually  plumose  stigmas;  fruit  a  caryopsis  with  starchy  endosperm 
and  a  small  embryo  at  the  base  on  the  side  opposite  the  hilum. 

Herbs,  or  rarely  woody  plants,  with  usually  hollow  stems  (culms) 
closed  at  the  nodes,  and  2-ranked  parallel-veined  leaves^  these  con- 
sisting of  2  parts,  the  sheath,  enveloping  the  culm,  its  margins  over- 
lapping or  sometimes  grown  together,  and  the  Made,  usually  flat; 
between  the  two  on  the  inside,  a  membranaceous  hyaline  or  hairy 
appendage  (the  liguZe) . 

The  spikelets  are  almost  always  aggregated  in  spikes  or  panicles 
at  the  ends  of  the  main  culms  or  branches.  The  perianth  is  usually 
represented  by  2  (rarely  3)  small  hyaline  scales  (the  lodicules)  at 
the  base  of  the  flower  inside  the  lemma  and  palea.  The  grain  or 


6  BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 

cjiryopsis  (the  single  seed  and  the  adherent  pericarp)  may  be  free, 
as  in  wheat,  or  permanently  inclosed  in  the  lemma  and  palea.  as  in 
the  oat.  Rarely  the  seed  is  free  from  the  pericarp,  as  in  species  of 
Sporobolus  and  Eleusine.  The  culms  of  bamboos  are  woody,  as  are 
also  those  of  a  few  genera,  such  as  Olyra  and  Lasiacis,  belonging  to 
other  tribes.  The  culms  are  solid  in  our  species  of  the  tribes  Trip- 
saceae  and  Andropogoneae.  The  margins  of  the  sheaths  are  grown 
together  in  species  of  Bromus,  Danthonia.  Festuca,  Melica,  Panicu- 
laria,  and  other  genera. 

The  parts  of  the  spikelet  may  be  modified  in  various  ways.  The 
first  glume,  and  more  rarely  also  the  second,  may  be  wanting.  The 
lemmas  may  contain  no  flower,  or  even  no  palea,  or  may  be  reduced 
or  rudimentary.  Rarely,  as  in  species  of  Agrostis  and  Andropogon, 
the  palea  is  obsolete. 

Most  of  the  genera  of  grasses  fall  naturally  into  one  of  the  two 
series  or  subfamilies.  The  remaining  few  are  rather  arbitrarily  as- 
signed to  one  or  the  .other  series.  In  the  same  manner,  most  of  the 
genera  may  be  assembled  into  distinct  and  wTell-marked  tribes,  but 
several  are  not  closely  allied  to  the  other  genera  in  the  tribe  to  which 
the}7  are  assigned  but  are  so  placed  for  convenience  in  classification. 

DESCRIPTIONS  OF  THE  SUBFAMILIES  AND  KEYS  TO  THE  TRIBES. 

SUBFAMILY  1,  POATAE. 

Spikelets  1  to  many  flowered,  the  reduced  florets,  if  any.  above  the 
perfect  florets  (except  in  Phalarideae ;  sterile  lemmas  below  as  well 
as  above  in  Campulosus,  TJniola,  and  Blepharidachne)  ;  articulation 
usually  above  the  glumes;  spikelets  usually  more  or  less  laterally 
compressed. 

Key  to  the  t riles  of  Poatae. 

riiints  woody,  the  culms  perennial;  spikelets  several-flowered. 

1.  Bamboseae  (p.  22). 
Plants  herbaceous,  the  culms  annual. 

Spikelets  with  2  staminate,  neuter,  or  rudimentary  lemmas  unlike 
and  below  the  fertile  lemma;  no  sterile  or  rudimentary  rtoivts 

above 8.  Phalarideae   (p.  199). 

Spikelets  without  sterile  lemmas  below  the  perfect  floret   (or  these 
rarely  present  and  like  the  fertile -ones,  a  dissimilar  pair  below 
and  a  rudimentary  floret  above  in  Blepharidachue). 
Spikelets    unisexual,    articulate    below    the    glumes,    1-flowered, 

terete  or  nearly  so 10.  Zizanieae  (p.  200). 

Spikelets  perfect  (rarely  unisexual  but  then  not  as  above),  usu- 
ally articulate  above  the  glumes. 

Spikelets  articulate  below  the  glumes,  1-flowered,  very  flat, 
the  lemma  and  palea  about  equal,  both  keeled;  glumes 
small  or  wanting 9.  Oryzeae  (p.  204), 


GENERA  OF   GRASSES   OF   THE   UNITED   STATES.  7 

Spikelets  articulate  above  the  glumes  (rarely  below,  but  the 

glumes,  at  least  one,  well  developed). 
Spikelets  1-flowered  in  groups  (short  spikes)  of  2  to  5 
(single  in  Osterdamia),  the  groups  racemose  along 
a  main  axis,  falling  entire ;  lemma  and  palea  thin- 
ner than  the  glumes 6.  Nazieae  (p.  165). 

Spikelets  not  as  above. 

Spikelets  sessile  on  a  usually  continuous  rachis 
(short-pedicellate  in  Leptochloa;  the  rachis 
disarticulating  in  Monerina,  Phpliurus,  Hor- 
deum,  Sitanion,  and  a  few  species  of  allied 
genera). 
Spikelets  on  opposite  sides  of  the  rachis;  spike 

terminal,   single /. 3.  Hordeae    (p.   87). 

Spikelets  on  one  side  of  the  rachis ;  spikes  usu- 
ally more  than  1,  digitate  or  racemose. 

7.  Chlorideae  (p.  171). 

Spikelets  pedicellate  in  open  or  contracted,  some- 
times spikelike,  panicles  (sessile  and  distant 
in  Eragrostis  sessilispica) . 

Spikelets   1-flowered 5.  Agrostideae    (p.    121). 

Spikelets  2  to  many  flowered. 

Glumes  as  long  as  the  lowest  floret,  usually 
as  long  as  the  spikelet;  lemmas 
awned  from  the  back  (spikelets  awn- 
less  in  Koeleria  and  Sphenopholis). 

4.  Aveneae  (p.  106). 

Glumes  shorter  than  the  first  floret  (except 
in  Dissanthelium  with  ,long  rachilla 
joints)  ;  lemmas  awnless  or  awned 
from  the  tip  or  from  a  bifid  apex. 

2.  Festuceae  (p.  24). 

SUBFAMILY  2,   PANICATAE. 

Spikelets  with  one  perfect  terminal  floret  (disregarding  those  of 
.ne  few  monoecious  genera  and  the  st animate  and  neuter  spikelets) 
and  a  sterile  or  staminate  floret  below,  usually  represented  by  a  sterile 
lemma  only,  one  glume  sometimes  (rarely  both  glumes)  wanting; 
articulation  below  the  spikelets,  either  in  the  pedicel,  in  the  rachis,  or 
at  the  base  of  a  cluster  of  spikelets,  the  spikelets  falling  entire,  singly, 
in  groups,  or  together  with  joints  of  the  rachis;  spikelets,  or  at  least 
the  fruits,  more  or  less  dorsally  compressed. 

Key  to  the  tribes  of  Pamcatae. 

Glumes  membra  naceous,  the  sterile  lemma  like  the  glumes  in  texture. 
Fertile  lemma  and  palea  thinner  than  the  glumes;   sterile  lemma 

awned  from  the  notched  summit 11.  Melinideae   (p.  212). 

Fertile  lemma  and  palea  indurate  or  at  least  firmer  than  the  glumes. 

12.  Paniceae  (p.  213). 
Glumes  indurate ;  fertile  lemma  and  palea  hyaline  or  membranaceous,  the 

sterile  lemma  (when  present)  like  the  fertile  one  in  texture. 
Spikelets  unisexual,  the  pistillate  below,  the  staminate  above,  on  the 
same  inflorescence  or  in  separate  inflorescences. 

14.  Tripsaceae   (p.  280). 


8  BULLETIN    772,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 

Spikelets  in  pairs,  one  sessile  and  perfect,  the  other  pedicellate  and 
usually  staminate  or  neuter  (the  pedicellate  one  sometimes 
obsolete,  rarely  both  pedicellate)  ;  lemmas  hyaline. 

13.  Andropogoneae   (p.  1252). 

DESCRIPTIONS  OF  THE  TRIBES  AND  KEYS  TO  THE  GENERA. 

TRIBE  1,  BAMBOSEAE. 

The  tribe  which  includes  the  bamboos  is  for  the  most  part  confined 
to  the  Tropics  and  Subtropics.  One  genus  extends  into  the  southern 
United  States.  The  bamboos  have  woody  jointed,  usually  holloAV 
culms  either  erect  or  vinelike.  Some  of  the  larger  kinds  are  as  much 
as  a  foot  in  diameter  and,  100  feet  in  height.  The  common  economic 
species  of  the  Tropics,  such  as  Bambos  vulgaris  Schrad.  (Banibos 
bambos  (L.)  Wight),  because  of  the  large  hollow  culms  with  hard 
partitions  at  the  nodes  found  in  most  large  species,  can  be 
used  for  a  great  variety  of  purposes.  Many  kinds  of  bamboos 
are  cultivated  for  ornament  in  the  warmer  parts  of  the  United  States, 
especially  in  Florida  and  California.  Arundinaria  japonica  Sieb. 
and  Zucc.  with  several-flowered  spikelets,  and  a  few  species  of  Phyl- 
lostachys,  are  hardy  as  far  north  as  Washington.  They  form  dense 
masses  of  shoots,  usually  8  to  20  feet  high.  Phyllost achys  does  not 
usually  flower  in  this  country,  but  the  plants  can  be  distinguished  by 
the  internodes  which  are  flattened  on  one  side.  Bambusa  is  a  modi- 
fied spelling  of  the  original  Bambos. 

TRIBE  2,  FESTUCEAE. 

Spikelets  more  than  1-flowered,  usually  several-flowered,  in  open, 
narrow,  or  sometimes  spikelike  panicles;  lemmas  awnless  or  awned 
from  the  tip,  rarely  from  between  the  teeth  of  a  bifid  apex ;  rachilla 
usually  disarticulating  above  the  glumes  and  between  the  florets. 

A  large  and  important  tribe,  mainly  inhabitants  of  the  cooler 
regions.  The  lemma  is  divided  into  several  awns  in  Pappophorum 
and  its  allies,  is 'deeply  2-lobed  In  Triplasis  and  in  a  few  species  of 
Triodia,  3-lobed  in  Blepharidachne,  several-toothed  in  Orcuttia,  and 
slightly  2 -toothed  in  Bromus  and  a  few  other  genera,  the  awn,  when 
single,  arising  from  between  the  teeth.  The  paleas  are  persistent 
upon  the  continuous  rachilla  in  most  species  of  Eragrostis.  Sclero- 
pogon,  Monanthochloe,  Distichlis,  and  a  few  species  of  Poa  and 
Eragrostis  are  dioecious.  Gynerium,  Cortaderia,  Arundo,  and  Phrag- 
mites  are  tall  reeds.  In  Blepharidachne  there  is  a  pair  of  sterile 
florets  at  the  base  of  the  single  fertile  floret,  and  a  rudiment  above. 
In  some  species  of  Melica  there  is,  above  the  fertile  florets,  a  club- 
shaped  rudiment  consisting  of  one  or  more  sterile  lemmas.  In  Uniola 
there  arc  one  to  four  sterile  lemmas  below  the  fertile  ones.  In  Melica 
imperfecta  and  M.  torreyana  there  may  be  but  one  perfect  floret. 


GENERA   OF   GRASSES   OF   THE    UNITED   STATES. 

Key  to  the  genera  of  Festuceae. 

la.  Plants  dioecious,  the  sexes  very  dissimilar,  the  pistillate  lemmas  with 
3   long   twisted   divergent    awns,    the    staminate    lemma    awnless 

or  mucronate 30.  SCLEROPOGON. 

Ib.  Plants  with  perfect  flowers,  or,  if  dioecious,  the  sexes  not  dissimilar 

in  appearance 2 

2a.  Lemmas  divided  at  the  summit  into  5  to  several  awns  or  awn- 
like  lobes 3 

,°>;i.  Awnlike  lobes  5 ;  inflorescence  a  simple  erect  raceme.  29.  ORCUTTIA. 

3b.  Awns  9  or  more 4 

4a.  Awns  unmixed  with  awned  teeth ;  all  the  florets  falling 

attached,  their  awns  forming  a  pappuslike  crown,  only 
the  lowest  floret  fertile ;  panicles  narrow.  32.  PAPPOPHOBUM. 
4b.  Awns  mixed  with  awned  teeth;  florets  not  falling  at- 
tached,   the    rachilla   disarticulating   between    them; 

panicles   somewhat  open 31.  COTTEA. 

2b.  Lemmas  awnless,  with  a  single  awn,  or,  if  3,  the  lateral  awns 

minute 5 

5a.  Tall  stout  reeds  with  large  plumelike  panicles;  lemmas  or 

rnchilla  with  long  silky  hairs  as  long  as  the  lemmas G 

Ga.  Lemmas  hairy;   rachilla   naked 19.  ARUNDO. 

Gb.  Lemmas  naked;  rachilla  hairy 20.  PHRAGMITES. 

5b.  Low  or  rather  tall  grasses,  rarely  over  5  feet  tall 7 

7a.  Plants  dioecious,   perennial;   lemmas  glabrous;   grasses 

of  salt  or  alkaline  soils 8 

8a.  Plants  low  and  creeping;  spikelets  obscure,  scarcely 
differentiated     from     the     short     crowded     rigid 

leaves 16.  MONANTHOCHLOE. 

Sb.  Plants  erect  from  creeping  rhizomes;  spikelets  in  a 

narrow  simple  exserted  panicle 17.  DTSTICHLIS. 

7b.  Plants  not  dioecious  (except  in  a  few  species  of  Poa  with 

villous  lemmas  and  in  an  annual  species  of  Eragrostis)  _  9 

9a.  Spikelets  of  two  forms,  sterile  and  fertile  intermixed ; 

panicle  dense,  somewhat  one-sided 10 

lOa.  Fertile  spikelets  2  or  3  flowered ;  sterile  spike- 
lets  with  numerous  rigid  awn-tipped  glumes; 

panicle   dense   and   spikelike 22.  CYNOSTJRTTS. 

lOb.  Fertile  spikelets  with  1  perfect  floret,  long- 
awned ;  sterile  spikelets  with  many  obtuse 
glumes ;  panicle  branchlets  short,  nodding. 

23.  ACHYRODES. 

9b.  Spikelets  all  alike  in  the  same  inflorescence 11 

lla.  Lemmas  3-nerved,  the  nerves  prominent,  often 

hairy 12 

12a.  Inflorescence  a  few-flowered  head  or  capi- 
tate panicle  overtopped  by  the  leaves  or 
partly  concealed  in  them ;  lemmas  toothed 
or  cleft ;  low  plants  of  the  arid  regions, _        13 
13a.  Inflorescence  hidden  among  the  sharp- 
pointed    leaves,    not   woolly;    plants 

annual     (Chlorideae) 97.  MUNROA. 

13b.  Inflorescence  a  capitate  woolly  panicle, 

not  concealed  ;  plants  perennial 14 


10  BULLETIN   772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 

Key  to  the  genera  of  Festiweae — Continued. 
14a.  Lemmas  cleft  either  side  of  the  midnerve  to  near  the 
base,  the  lower  two  sterile,  the  third  floret  fertile,  the 
fourth  reduced  to  a  3-awned  rudiment-  28.  BLEPHABIDACHNE. 
14b.  Lemma  2-lobed  but  not  deeply  cleft,  all  fertile  but  the 

uppermost 26.  TEIODIA. 

12b.  Inflorescence  an  exserted  open  or  spikelike  panicle 15 

15a.  Lemmas  pubescent  on  the  nerves  or  callus  (except  in  Tri- 
*odia  albescens),  the  midnerve  usually  exserted  as  an  awn 

or  mucro 16 

16a.  Nerves  glabrous;  callus  densely  hairy;   lemmas  firm; 

panicle  large,  diffuse 15.  REDFIELDIA. 

16b.  Nerves   hairy    at   least   below,   the   lateral   ones   often 

conspicuously  so 17 

17a.  Palea  long-ciliate  on  the  upper  half 27.  TRIPLASIS. 

17b.  Palea  sometimes  villous  but  not  lorig-ciliate  on  the 

upper  half;  perennials 26.  TEIODIA. 

15b.  Lemmas  not  pubescent  on  the  nerves  nor  callus  (the  inter- 
nerves  sometimes  pubescent),  awnless IS 

18a.  Glumes  longer  than  the  lemmas ;  lateral  nerves  of  lemma 

marginal,  the  internerves  pubescent 14.  DISSANTHELIUM. 

ISb.  Glumes  shorter   than   the  lemmas;   lateral  nerves   not 

marginal,  the  internerves  glabrous 19 

19a.  Lemmas  chartaceous;  grain  large  and  beaked,  at 

maturity  forcing  the  lemma  and  palea  open_  13.  DIAEINA. 
19b.  Lemmas  membranaceous ;  if  firm,  the  grain  neither 

large  nor  beaked 20 

20a.  Spikelets    subterete;    palea    longer    than    the 

lemma,  bowed  out  below 12.  MOLINIA. 

20b.  Spikelets  compressed ;  palea  not  longer  than  the 

lemma,  not  bowed  out  below 21 

21a.  Lemmas  truncate ;  spikelets  2-flowered. 

11.  CATABBOSA. 

21b.  Lemmas  acute  or  acuminate;  spikelets  3 
to  many  flowered ;  rachilla  continuous, 
the  paleas  usually  persistent  after  the 

fall  of  the  lemmas 10.  EEAGEOSTIS. 

111).  Lemmas  5  to  many  nerved,  the  nerves  sometimes  obscure 22 

22a.  Spikelets  with  1  to  4  empty  lemmas  below  the  fertile  florets; 

nerves  obscure;  lemmas  firm 18.  UNIOLA. 

22b.  Spikelets  with  no  empty  lemmas  below  the  fertile  florets ;  nerves 
usually  prominent;   lemmas  membranaceous    (firm   in  a  few 

species  of  Bromus  and  Festuca) 23 

23a.  Lemmas   flabellate;    glumes   wanting;   inflorescence  dense, 

cylindric;  low  annual 25.  ANTHOCHLOA. 

23b.  Lemmas  not  flabellate;   glumes  present;   inflorescence  not 

cylindric 24 

24a.  Palea  winged  on  the  lower  half  of  the  keels;  spikelets 

linear,  in  a  loose  raceme 5.  PLEUEOPOGON. 

24b.  Palea  not  winged  on  the  lower  half  of  the  keels;  in- 
florescence mostly  paniculate 25 

25a.  Lemmas  as  broad  as  long,  the  margins  outspread; 

florets  closely  imbricate,  horizontally  spreading-    9.    BBIZA. 
25b.  Lemmas  longer  than  broad,  the  margins  clasping 

the  palea  ;  florets  not  horizontally  spreading 26 


GENEKA   OF   GRASSES   OF   THE   UNITED   STATES.  11 

Key  to  the  genera  of  Festuceae — Continued. 

2Ga.  Callus  of  florets  bearded  ;  lemmas  erose  at  the  summit 7.  FLUMINEA. 

26b.  Callus  not  bearded  (lemmas  cobwebby  at  base  in  Poa)  ;  lemmas  not 

erose    (slightly  in   Puccinellia) 27 

27a.  Lemmas  keeled  on  the  back  (somewhat  rounded  in  Poa  scabrella 

and  its  allies) 28 

28a.  Spikelets  strongly  compressed,  crowded  in  one-sided  clusters 

at  the  ends  of  the  stiff,  naked  panicle  branches 21.  DACTYLIS. 

28b.  Spikelets  not  strongly  compressed,  not  crowded  in  one-sided 

clusters 29 

29a.  Lemmas  awned  from  a  minutely  bifid  apex  (awnless  or 
nearly  so  in  Bromus  unioloides  and  B.  brizaeformis)  ; 

spikelets    large 2.  BROMUS. 

20b.  Lemmas  awnless ;  spikelets  small 8.  POA.  ' 

27b.  Lemmas  rounded  on  the  back  (slightly  keeled  toward  the  summit 

in  Festuca  and  Bromus) 30 

30a.  Glumes  papery  ;  lemmas  firm,  strongly  nerved,  scarious-mar- 
gined ;  upper  florets  sterile,  often  reduced  to  a  club-shaped 
rudiment  infolded  by  the  broad  upper  lemmas;  spikelets 

tawny  or  purplish,  usually  not  green 24.  MELICA. 

30b.  Glumes  not  papery  ;  upper  florets  not  unlike  the  others 31 

31a.  Nerves  of  the  lemma  parallel,  not  converging  at  the  sum- 
mit or  but  slightly  so ;  lemmas  awnless  mostly  obtuse.        32 
32a.  Nerves  prominent ;  plants  usually  rather  tall,  grow- 
ing in  woods  or  fresh-water  marshes 4.  PANICULARIA. 

32b.  Nerves  faint ;  plants  low,  growing  in  saline  soil. 

6.  PUCCINELLIA. 

31b.  Nerves  of  the  lemma  converging  at  the  smmmit ;  lemmas 
awned  or  pointed  (upper  florets  only  minutely  awn- 
tipped  in  Bromus  brizaeformis) 33 

33a.  Lemmas   entire,    awned    from    the   tip   or   pointed 
(minutely    toothed    in    Festuca    elmeri    and    F. 

gigantea} 3.  FESTUCA. 

33b.  Lemmas  awned  or  awn-tipped  from  a  minutely  bifid 

apex 2.  BROMTJS. 

TRIBE  3,  HORDEAE. 

Spikelets  1  to  several  flowered,  sessile  on  opposite  sides  of  a  jointed 
or  continuous  axis  forming  symmetrical  (not  one-sided)  spikes. 

This  small  but  important  tribe,  found  in  the  temperate  regions  of 
both  hemispheres,  includes  our  most  important  cereals,  wheat,  barley, 
and  rye.  The  rachis  is  flattened  or  concave  next  to  the  spikelets,  or 
in  some  genera  is  thickened  and  hollowed  out,  the  spikelets  being 
more  or  less  inclosed  in  the  hollows.  In  Triticum  and  its  allies  there 
is  one  spikelet  at  each  node  of  the  rachis;  in  Hordeum  and  its  allies 
there  are  two  or  three  at  each  node.  In  Lolium  and  its  allies  the 
spikelets  are  placed  edgewise  to  the  rachis,  and  the  first  or  inner 
glume  is  suppressed  except  in  the  terminal  spikelet.  The  rachilla  of 
the  spikelet  disarticulates  at  maturity  in  several  genera.  In  some 
species  of  Elymus  and  especially  in  Sitanion  the  glumes  are  very 


12-  BULLETIN   772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 

slender,  extending  into  long  awns,  in  the  latter  genus  sometimes 
divided  into  several  slender  bristles.  In  this  tribe  the  blades  of  the 
leaves  bear  on  each  side  at  the  base  a  small  appendage  or  auricle. 

Key  to  the  genera  of  Hordeae. 

la.  Spikelets  solitary  at  each  node  of  the  rachis  (rarely  2  in  species  of 

Agropyron,  but  never  throughout) 2 

2a.  Spikelets   1-flowered,    sunken   in  hollows   in  the   rachis;    spikes 

slender,  cylindric;  low  annuals 3 

3a.  Lemmas  awned ;   florets  lateral  to  the  rachis 36.  SCRIBNKRIA. 

3b.  Lemmas  awnless ;  florets  dorsiventral  to  the  rachis 4 

4a.  First  glume  wanting 42.  LEPTUBTJS. 

4b.  First  glume  present,  the  pair  standing  in  front  of  the 

spikelet 43.  PIIOLIURUS. 

2b.  Spikelets  2  to  several  flowered,  not  sunken  in  the  rachis 5 

5a.  Spikelets  placed  edgewise  to  the  rachis ;  first  glume  wanting 

except  in  the  terminal  spikelet 41.  LOT.ITJM.  " 

5b.  Spikelets  placed  flatwise  to  the  rachis G 

6a.  Plants    perennial i 33.  AGROPYRON. 

6b.  Plants    annual 7 

7a.  Glumes  ovate,  3-nerved 34.  TRTTICUM. 

7b.  Glumes  subulate,  1-nerved 3.1.  SKCAI.K.  v 

Ib.  Spikelets  more  than  1  at  each  node  of  the  rachis 8 

8a.  Spikelets  3  at  each  node  of  the  rachis,   1-flowered,  the  lateral 

pair  pediceled,  usually  reduced  to  awns 40.  HORDEUM.  * 

8b.  Spikelets  2  at  each  node  of  the  rachis,  alike,  2  to  6  flowered 9 

9a.  Glumes  wanting  or  reduced  to  2  short  bristles ;  spikelets  hor- 
izontally spreading  at  maturity  ;  spikes  very  loose 39.  HYSTRIX. 

9b.  Glumes  usually  equaling  the  florets;  spikelets  appressed  or 

ascending    10 

lOa.  Rachis    continuous     (rarely    tardily    disarticulating)  ; 

glumes  broad  or  narrow,  entire 37.  ELYMTJS. 

lOb.  Rachis  disarticulating  at  maturity;  glumos  subulate, 
extending  into  long  awns,  these  and  the  awns  of  the 
lemmas  making  the  spike  very  bristly 38.  STTAXIOX.  * 

Tin  in:  4,  AVKXKAE. 

Spikelets  2  to  several  flowered  in  open  or  contracted  panicles,  or 
rarely  in  racemes  (solitary  in  Danthonia  unispicata)  ;  glumes  usually 
as  long  as  or  longer  than  the  first  lemma,  commonly  longer  than  all 
the  florets;  lemmas  usually  awned  from  the  back  or  from  between 
the  teeth  of  a  bifid  apex,  the  awn  bent,  often  twisted,  the  callus  and 
rachilla  joints  usually  villous. 

A  rather  small  tribe  widely  distributed  in  both  warm  and  cool 
regions.  In  our  genera  the  rachilla  is  prolonged  beyond  the  upper 
floret  as  a  slender  stipe  (except  in  Aspris).  The  lemma  is  awnless 
or  nearly  so  in  Sphenopholis  and  in  our  species  of  Koeleria.  These 
genera  are  placed  in  this  tribe  because  they  appear  to  be  closely 
allied  to  Trisetum  with  which  they  agree  in  having  oblanceolate 
glumes  about  as  long  as  the  first  floret. 


GENERA   OF    GRASSES    OF   THE    UNITED   STATES.  13 

Key  to  the  genera  of  Avcncae. 

la.  Spikelets  awnless  or  the  upper  lemma  mucronate  (rarely  short-awned 

in    Splienopliolis) 2 

2a.  Articulation    bolow    the   glumes ;    glumes   distinctly   different   in 

shape,  the  second  widened  above 4G.  SIMIKMOPIIOLIS. 

2b.  Articulation  above  the  glumes;  glumes  similar  in  shape,   44.  KOKLKKIA. 

Ib.  Spikelets  awned   (awnless  in  Trisetum  wolfii) 3 

3u.  Florets  2,  one  perfect,  the  other  staminate 4 

4a.  Lower   floret   staminate,   the   awn   twisted,   geniculate,   ex- 
sorted 48.    ARRHENATHERUM. 

4b.  Lower  floret  perfect,  awnless;  awn  of  upper  floret  hooked. 

51.  NOTHOLCUS. 

3b.  Florets  2  or  more,  all  alike  except  the  reduced  upper  ones 5 

5a.  Awn  arising  from  between  the  teeth  of  a  bifid  apex,  flat- 
tened, twisted ;  inflorescence  a  simple  panicle  or  reduced 

to  a  raceme  or  even  to  a  single  spikelet 52.  DANTHONIA. 

5b.  Awn  dorsal,  not  flattened  ;  lemma  often  bifid  at  apex G 

6a.  Spikelets  large,  the  glumes  over  1  cm.  long 47.  AVENA.*-*' 

6b.  Spikelets  less  than  1  cm.  long 7 

7a.  Lemmas  keeled,  bidentate;  awn  arising  from  above 

the  middle 45.  TRISETUM. 

7b.  Lemmas  convex ;  awn  from  below  the  middle 8 

8a.  Rachilla  prolonged  behind  the  upper  floret;  lem- 
mas truncate  and  erose-dentate  at  summit 49.  AIRA. 

8b.  Rachilla  not  prolonged ;  lemmas  tapering  into  2 

slender  teeth 50.  ASPRIS.  , 

TRIBE  5,  AGROSTIDEAE. 

Spikelets  1-flowered,  usually  perfect,  arranged  in  open,  contracted, 
or  spikelike  panicles,  but  not  in  true  spikes  nor  in  one-sided  racemes. 

A  large  and  important  tribe,  inhabiting  more  especially  the  tem- 
perate and  cool  regions.  The  articulation  of  the  rachilla  is  usualty 
above  the  glumes,  the  mature  floret  falling  from  the  persistent 
glumes,  but  in  a  few  genera  the  articulation  is  below  the  glumes,  the 
mature  spikelet  falling  entire  (Alopecurus,  Cinna,  Polypogon, 
Lycurus,  and  Limnodea).  The  palea  is  small  or  wanting  in  some 
species  of  Agrostis.  In  a  few  genera  the  rachilla  is  prolonged 
behind  the  palea  as  a  minute  bristle,  or  sometimes  as  a  more  pro- 
nounced villous  stipe  (Brachyelytrum,  Limnodea,  Cinna,  three  species 
of  Agrostis,  Gastridium,  Calamagrostis,  Ammophila,  and  Lagurus). 
In  some  genera  the  rachilla  joint  between  the  glumes  and  the  lemma 
is  slightly  elongated,  forming  a  hard  stipe  which  remains  attached 
to  the  mature  fruit  as  a  pointed  callus.  The  callus  is  well  marked 
in  Stipa  (especially  in  S.  spartea  and  its  allies)  and  in  Aristida,  the 
mature  lemma  being  terete,  indurate,  and  convolute,  the  palea  wholly 
inclosed.  In  many  genera  the  lemma  is  awned  either  from  the  tip 
or  from  the  back,  the  awn  being  trifid  in  Aristida. 


14  BULLETIN   772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 

Key  to  the  genera  of  Agrostideae. 

la.  Glumes  wanting;  a  low  annual 58.  COLEANTHTTS. 

Ib.  Glumes   present    (the  first   obsolete   in    ^fuJllcnJ)crgia    scJircbcri   and 

sometimes  in  Brachyelytrum  and  Phippsia) 2 

2a.  Rachilla   articulate   below   the   glumes,   these   falling   with  the 

spikelet 3 

3a.  Spikelets  in  pairs  in  a   spikelike  panicle,  one  perfect,   the 

other  staminate  or  neuter,  the  pair  falling  together-  63.  LYCUBUS. 

3b.  Spikelets  all  alike 4 

4a.  Glumes  long-awned_: 62.  POLYPOGON. 

4b.  Glumes  awnless 5 

5a.  Rachilla  not  prolonged  behind  the  palea ;  panicle 
dense  and  spikelike ;  glumes  united  toward  the 

base,  ciliate  on  the  keel 61.  ALOPECURUS. 

5b.  Rachilla  prolonged  behind  the  palea ;  panicle  nar- 
row or  open,  not  dense;  glumes  not  united,  not 

ciliate  on  the  keel , 6 

6a.  Panicle    narrow;    lemma    with    a    slender   bent 

twisted  awn  from  the  bifid  apex 60.  LIMNODEA. 

6b.  Panicle  open  and  drooping ;  lemma  with  a  minute 

straight  awn  just  below  the  entire  apex 59.  CINNA. 

2b.  Rachilla  articulate  above  the  glumes 7 

7a.  Fruit   dorsally    compressed,    indurate,    smooth    and    shining, 

awnless 74.  MILIUM. 

7b.  Fruit  laterally  compressed  or  terete,  awned  or  awnless 8 

8a.  Fruit  indurate,  terete,  awned,  the  nerves  obscure ;  callus 

well  developed,  oblique,  bearded 9 

9a.  Awn  trifid,  the  lateral  divisions  sometimes  short, 
rarely  obsolete  (when  obsolete  no  line  of  demar- 
cation between  awn  and  lemma  as  in  the 

next) 77.  ABISTIDA. 

9b.  Awn  simple,  a  line  of  demarcation  between  the  awn 

and  the  lemma 10 

lOa.  Awn  persistent,   twisted  and  bent,   several  to 
many  times  longer  than  the  slender  fruit ;  callus 

sharp-pointed 76.  STIPA. 

lOb.  Awn  deciduous,   not  twisted,   sometimes  bent, 
rarely  more  than  3  or  4  times  as  long  as  the 
plump  fruit ;  callus  short,  usually  obtuse-  75.  ORYZOPSIS. 
8b.  Fruit  thin  or  firm,  but  scarcely  indurate,   if  firm,  the 
nerves  prominent  or  evident ;   callus  not  well  devel- 
oped           11 

lla.  Glumes  longer  than  the  lemma  (lemma  equaling 
the  glumes  in  Agrostis  spica-venti,  A.  aequivalvis, 

and  A.  thurberiana) 12 

12a.  Panicle  feathery,  capitate,  nearly  as  broad  as 

long;    spikelets   woolly 66.  LAGURUS. 

12b.  Panicle  not  feathery;  spikelets  not  woolly 13 

13a.  Glumes  compressed-carinate,  abruptly  mu- 
cronate,     stiffly     ciliate     on     the     keels; 
panicle  dense,  cylindric  or  ellipsoid-  64.  PHLEUM. 
13b.  Glumes  not  compressed-carinate,  not  ciliate         14 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  15 

Key  to  the  genera  of  Agrostideae — Continued. 

14a.  Glumes  saccate  at  base ;  lemma  long-awned  ;  inflorescence 

contracted,  shining 65.  GASTEIDIUM. 

14b.  Glumes  not  saccate  at  base ;  lemma  awned  or  awnless ; 

panicles  open  or  contracted ] 15 

15a.  Florets  bearing  a  tuft  of  hairs  at  the  base  from  the 
short  callus,  the  hairs  at  least  half  as  long  as  the 

lemma;  palea  present 53.  CALAMAGBOSTIS. 

15b.  Florets  without  hairs  at  the  base  or  with  short 
hairs  rarely  as  much  as  half  the  length  of  the 
lemma  (Agrostis  hallii)  ;  palea  usually  small  or 

wanting 56.  AGROSTIS.   " 

lib.  Glumes  not  longer  than  the  lemma,  usually  shorter   (the  awn  tips 

longer  in  Muhlenbergia  racemosa) 16 

16a.  Lemma  awned  from  the  tip  or  mucronate,  3  to  5  nerved  (lateral 

nerves  obsolete  in  Muhleribergia  rcpcns) 17 

17a.  Rachilla  prolonged  behind  the  palea;   floret  stipitate. 

73.  BBACHYELYTETJM. 

17b.  Rachilla  not  prolonged ;  floret  not  stipitate 68.  MUHLENBERGIA. 

16b.  Lemma  awnless  or  awned  from  the  back 'i,        18 

18a.  Florets  bearing  a  tuft  of  hairs  at  the  base  from  the  short 

callus;  lemma  and  palea  chartaceous,  awnless 19 

19a.  Panicles  spikelike;  rachilla  prolonged 54.  AMMOPHILA. 

19b.  Panicles  open ;  rachilla  not  prolonged 55.  CALAMOVILFA. 

18b.  Florets  without  hairs  at  base 20 

20a.  Nerves  of  lemma  densely  silky 70.  BLEPHARONEURON. 

20b.  Nerves  of  lemma  not  silky 21 

21a.  Caryopsis  at  maturity  falling  from  the  lemma  and 
palea;  seed  loose  in  the  pericarp,  this  usually 

opening  when  ripe;  lemma  1-nerved 22 

22a.   Inflorescence  capitate  in   the  axils  of  broad 

bracts 71.  CRYPSIS. 

22b.  Inflorescence  an  open  or  contracted  panicle. 

69.  SPOROBOLUS. 

21b.  Caryopsis  not  falling  from  the  lemma  and  palea, 
remaining  permanently  inclosed  in  them;  seed 

adnate  to  the  pericarp 23 

23a.  Panicles  few-flowered,  slender,  rather  loose; 
glumes  minute,  unequal,  the  first  often  want- 
ing; a  low  arctic  alpine  perennial 57.  PHIPPSIA. 

23b.  Panicle  many-flowered,  spikelike ;  glumes  well 

developed,    about   equal 24 

24a.  Panicle  short,  partly  inclosed  in  the  sheath ; 

low    annual 72.  HELEOCHLOA. 

24b.  Panicle  elongate;  perennial 67.  EPICAMPES. 

TRIBE  6,  NAZIEAE. 

Spikelets  subsessile  in  short  spikes  of  2  to  5  (single  in  Oster- 
damia),  each  spike  falling  entire  from  the  continuous  axis,  usually 
1-flowered,  all  perfect,  or  perfect  and  staminate  together  in  the  same 
spike;  glumes  usually  firmer  than  the  lemma  and  palea,  sometimes 
awned,  the  lemma  awnless. 

This  small  and  unimportant  tribe  is  known  also  as  Zoysieae.  In 
Osterdamia  the  spikelets  are  single  and  have  only  one  glume,  this 


16  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

coriaceous,  much  firmer  than  the  lemma  and  palea,  the  palea  some- 
times obsolete. 

Key  to  the  yenera  of  Nazieae. 

la.  Spikelets  single ;  first  glume  wanting 79.  OSTERDAMIA. 

Ib.  Spikelets  in  clusters  of  2  to  5  ;  first  glume  present 2 

2a.  Spikelets  bearing  hooked  spines  on  the  second  glume,  the  group 

forming  a  little  bur 78.  NAZIA. 

2b.  Spikelets  not  bearing  hooked  spines,  mostly  cleft  and  awned 3 

3a.  Groups  of  spikelets  erect,  the  spike  not  one-sided 80.  HILABIA. 

3b.  Groups  of  spikelets  nodding  along  one  side  of  the  delicate 
axis 81.  AEGOPOGON. 

TRIBE  7,  CHLOKIDEAE. 

Spikelets  1  to  several  flowered,  in  2  rows  on  one  side  of  a  con- 
tinous  rachis  forming  one-sided  spikes  or  spikelike  racemes,  these 
solitary,  digitate,  or  racemose  along  the  main  axis. 

A  large  and  rather  important  tribe,  confined  mostly  to  warm 
regions.  The  group  is  heterogeneous,  the  only  common  character 
of  the  genera  (aside  from  the  characters  that  place  them  in  Poatae) 
being  the  arrangement  of  the  spikelets  in  one-sided  spikes.  Chloris 
and  the  allied  genera  form  a  coherent  group,  in  which  the  spikelet 
consists  of  one  perfect  floret  and,  above  this,  one  or  more  modified 
or  rudimentary  florets.  Leptochloa,  Eleusine,  and  their  allies,  with 
several-flowered  spikelets,  are  more  nearly  related  to  certain  genera 
of  Festuceae.  The  spike  is  reduced  to  two  or  three  spikelets  or  even 
to  one  spikelet  and  is  sometimes  deciduous  from  the  main  axis  in 
Cathestecum  and  in  some  species  of  Bouteloua.  In  Campulosus 
there  are  two  sterile  florets  below  the  perfect  one. 

Key  to  the  genera  of  Chlorideae. 

la.  Plants  monoecious  or  dioecious ;  a  low  stoloniferous  perennial-  98.  BTJLBIUS. 

Ib.  Plants  with  perfect  flowers 2 

2a.  Spikelets  with  more  than  one  perfect  floret 3 

3a.  Inflorescence  a  few-flowered  head  or  capitate  panicle  hidden 
among  the  sharp-pointed  leaves;  a  low  spreading  an- 
nual  97.  MUNBOA. 

3b.  Inflorescence   exserted 4 

4a.  Spikes  solitary,    the   spikelets   distant,   appressed,   sev- 
eral-flowered  83.  TEIPOGON. 

4b.  Spikes  more  than  1 5 

5a.  Spikes  numerous,  slender,  racemose  on  an  elongate 

axis 82.  LEPTOCHLOA. 

5b.  Spikes  few,  digitate  or  nearly  so 6 

6a.  Rachis   of   spike   extending   beyond   the  spike- 
lets 85.  DACTYLOCTENITJM. 

6b.  Rachis  not  prolonged 84.  ELEUSINE. 

2b.  Spikelets  with  only  1  perfect  floret,  often  with  additional  imper- 
fect florets  above__  7 


GENEKA   OF   GRASSES   OF   THE   UNITED   STATES.  17 

Key  to  the  genera  of  Chlorideac — Continued. 

7a.  Spikelets  without  additional  modified  florets,  the  rachilla  sometimes 

prolonged 8 

Sa.  Rachilla  articulate  below  the  glumes,  the  spikelets  falling  entire-          9 

9a.  Glumes  unequal,  narrow 90.  SPAETINA. 

9b.  Glumes  equal,  broad  and  boat  shaped 89.  BECKMANNIA. 

8b.  Rachilla  articulate  above  the  glumes 10 

lOa.  Spikes  digitate;  rachilla  prolonged 86.  CAPRIOLA. 

lOb.  Spikes  racemose  along  the  main  axis ;  rachilla  not  prolonged.        11 
Ha.  Spikes  slender,  divaricate,  the  main  axis  elongating  and 

becoming  loosely  spiral  in  fruit 88.  SCHEDONNARDUS. 

lib.  Spikes  short  and  rather  stout,  appressed,  the  axis  un- 
changed in  fruit 87.  WUXKOMMIA. 

7b.  Spikelets  with  1  or  more  modified  florets  above  the  perfect  one_ 12 

12a.  Spikelets  with  2  sterile  florets  below  the  perfect  one;  second 
glume  bearing  a  squarrose  spine  on  the  back;   spike  single, 

recurved 91.  CAMPULOSUS. 

12b.  Spikelets  with  no  sterile  florets  below  the  perfect  one;  second 

glume  without  a  squarrose  spine ;  spikes  usually  several 13 

13a.  Spikes  digitate  or  nearly  so 14 

14a.  Fertile  lemma  1-awned  or  awnless 93.  CHLOBIS. 

14b.  Fertile  lemma  3-awned 94.  TKICHLOEIS. 

13b.  Spikes  racemose  along  the  main  axis 15 

15a.  Spikelets  distant,  appressed ;  spikes  slender,  elongate. 

92.  GYMNOPOGON. 
15b.  Spikelets  contiguous  or  crowded,  not  appressed ;  spikes 

usually  short  and  rather  stout -. 16 

16a.  Spikelets  3  in  each  spike,  the  2  lateral  staminate  or 

rudimentary ;  spikes  falling  entire 96.  CATHESTECUM. 

16b.  Spikelets  2  to  many   (rarely  1)   in  each  spike,  all 
alike ;  spikes  usually  persistent,  the  florets  falling. 

95.  BOUTELOUA. 

TRIBE  8,  PHALARIDEAE. 

Spikelets  with  one  perfect  terminal  floret  and,  below  this,  a  pair  of 
staminate  or  neuter  florets. 

A  small  tribe  of  about  six  genera,  only  three  of  which  are  found 
in  the  United  States.  In  Phalaris  the  lateral  florets  are  reduced  to 
minute  scalelike  lemmas  closely  appressed  to  the  edges  of  the  fertile 
floret.  In  Torresia  the  lateral  florets  are  staminate  and  as  large  as 
the  fertile  floret. 

Key  to  the  genera  of  Phalarideae. 

la.  Lateral  florets  staminate ;  spikelets  brown  and  shining 99.  TORRESIA. 

Ib.  Lateral  florets  neuter ;  spikelets  green  or  yellowish 2 

2a.  Lateral  florets  reduced  to  small  awnless  scalelike  lemmas ;  spike- 
lets  much  compressed  laterally -  101.  PHALARIS. 

2b.  Lateral  florets  consisting  of  awned  hairy  sterile  lemmas  exceed- 
ing the  fertile  floret ;  spikelet  terete 100.  ANTHOXANTHTJM, 

97769°— 19— Bull.  772 2 


18  BULLETIN    112,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

TRIBE  9,  ORYZEAE. 

Spikelets  1-flowered,  perfect,  strongly  laterally  compressed,  panic- 
ulate ;  glumes  reduced  or  wanting ;  palea  apparently  1-nerved ;  stam- 
ens 6. 

A  small  tribe  whose  affinities  are  not  evident.  It  includes  rice,  the 
important  food  plant. 

-     Key  to  the  genera  of  Oryzeae. 

Glumes  minute;  lemma  often  awned 102.  ORYZA. 

Glumes  wanting;   lemma  awnless 103.  HOMALOCENCHRUS. 

TRIBE  10,  ZIZANIEAE. 

Spikelets  unisexual,  the  pistillate  terete  or  nearly  so;  glumes 
shorter  than  the  lemma,  usually  one  or  both  obsolete,  the  pedicel  dis- 
articulating below  the  spikelet. 

A  small  tribe  of  uncertain  affinities;  the  species  aquatic  or  sub- 
aquatic,  of  no  economic  importance  except  the  Indian  rice  (Zizania). 

Key  to  the  genera  of  Zizanieae. 

la.  Culms  slender ;  plants  low ;  staminate  and  pistillate  spikelets  borne  in 

separate  inflorescences 2 

2a.  Inflorescence  a  few-flowered  spike ;  plants  not  stoloniferous. 

107.  HYDROCHLOA. 

2b.  Inflorescence  a  panicle;  plants  stoloniferous 106.  LUZIOLA. 

Ib.  Culms  robust ;  plants  tall ;  staminate  and  pistillate  spikelets  borne  in 

the  same  panicle - 3 

3a.  Plants    annual;    pistillate    spikelets    on    the    ascending    upper 
branches,  the  staminate  on  the  spreading  lower  branches  of  the 

panicle '. 105.  ZIZANIA. 

3b.  Plants  perennial;  pistillate  spikelets  at  the  ends,  the  staminate 

below  on  the  same  branches  of  the  panicle 104.  ZIZANIOPSIS. 

TRIBE  11,  MELINIDEAE. 

Spikelets  disarticulating  below  the  glumes,  these  very  unequal,  the 
first  minute,  the  second  and  the  sterile  lemma  equal,  membranaceous, 
strongly  nerved,  the  latter  bearing  a  slender  awn  from  the  notched 
summit ;  fertile  lemma  and  palea  thinner  in  texture,  awnless. 

A  tribe  of  about  a  dozen  genera,  none  of  wrhich  is  represented  in 
the  United  States.  The  only  economic  species  is  Melinis  minutiftora 
(seep.  212). 

TRIBE  12,  PANICEAE. 

Spikelets  with  one  perfect  terminal  floret  and  below  this  a  sterile 
floret  and  two  glumes;  fertile  lemma  and  palea  indurate  or  at  least 
firmer  than  the  glumes  and  sterile  lemma;  articulation  below  the 
spikelet. 

A  large  tribe,  confined  mostly  to  warm  regions,  and  containing  few 
economic  species.  The  first  glume  is  wanting  in  some  genera,  such 
as  Paspalum,  and  rarely  the  second  glume  also  (Eeimarochloa). 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES.  19 

The  spikelets  are  usually  awnless,  but  the  glumes  and  sterile  lemma 
are  awned  in  Echinochloa  and  Oplismenus,  and  the  second  glume  and 
sterile  lemma  in  Tricholaena.  In  Eriochloa  and  in  some  species  of 
Brachiaria  the  fertile  lemma  is  awn-tipped.  In  Chaetochloa  there 
are,  beneath  the  spikelet,  one  or  more  bristles,  these  representing 
sterile  branchlets.  In  Pennisetum  similar  bristles  form  an  involucral 
cluster,  falling  with  the  spikelet.  In  Cenchrus  the  bristles  are 
united,  forming  a  bur.  The  spikelets  are  of  two  kinds  in  Amphi- 
carpon,  aerial  and  subterranean.  The  culms  are  woody  and  perennial 
in  Lasiacis  and  Olyra. 

Key  to  the  genera  of  Paniceae. 

la.  Spikelets  of  two  kinds 2 

2a.  Spikelets  all  perfect,  but  those  of  the  aerial  panicle  not  perfect- 
ing   grains;    the    fruitful    spikelets    borne    on    subterranean 

branches 127.  AMPHICARPON. 

2b.  Spikelets  unisexual,  the  pistillate  above,  the  staminate  below  on 
the  branches  of  the  same  panicle ;  blades  broad,  elliptic. 

OLYRA.     (See  p.  252.) 

Ib.  Spikelets  all  of  one  kind 3 

3a.  Spikelets  sunken  in  the  cavities  of  the  flattened  corky  rachis. 

112.  STENOTAPHEUM. 

3b.  Spikelets  not  sunken  in  the  rachis 4 

4a.  Spikelets  subtended  or  surrounded  by  1  to  many  distinct  or 

more  or  less  connate  bristles,  forming  an  involucre 5 

5a.  Bristles  persistent,  the  spikelets  deciduous-  124.  CHAETOCHLOA. 

5b.  Bristles  falling  with  the  spikelets  at  maturity G 

6a.  Bristles  not  united  at  base,  slender,  often  plumose. 

125.  PENNISETUM. 
6b.  Bristles  united  into  a  burlike  involucre,  the  bristles 

retrorsely  barbed 126.  CENCHRUS. 

4b.  Spikelets  not  subtended  by  bristles 7 

7a.  Glumes  or  sterile  lemma  awned    (awn  short  and  con- 
cealed in  the  silky  hairs  of  the  spikelet  in  Tricholaena, 

awn  reduced  to  a  point  in  Echinochloa  colonuni) 8 

8a.  Inflorescence  paniculate ;  spikelets  silky_  123.  TRICHOLAENA. 
8b.  Inflorescence  of  unilateral  simple  or  somewhat  com- 
pound racemes  along  a  common  axis;  spikelets 

smooth  or  hispid,  not  silky 9 

9a.  Blades  lanceolate,  broad  and   thin ;   glumes  2- 
lobed,  awned  from  between  the  lobes. 

121.  OPLISMENUS. 
9b.  Blades  long  and  narrow ;  glumes  awned  from 

the    tip 122.  ECHINOCHLOA. 

7b.  Glumes  and  sterile  lemma  awnless 10 

lOa.  Fruit  cartilaginous-indurate,  flexible,  usually  dark 
colored,  the  lemma  with  more  or  less  prominent 

white  hyaline  margins,  these  not  inrolled 11 

Ha.  Spikelets   covered   with   long  silky   hairs,    ar- 
ranged in  racemes,  these  panicled 109.  VALOTA. 

lib.  Spikelets  glabrous  or  variously  pubescent  but 

not  long-silky 12 


20  BULLETIN   772,    U.   S.   DEPARTMENT   OF   AGRICULTURE. 

Key  to  the  genera  of  Paniceae*— Continued. 

12a.  Spikelets  in  slender  racemes  more  or  less  digitate  at  the 

summit  of  the  culms 110.  SYNTHEBISMA. 

12b.  Spikelets  in  panicles 13 

13a.  Fruiting  lemma  boat  shaped;  panicles  narrow. 

108.  ANTHAENANTIA. 

13b.  Fruiting  lemmas  convex;  panicles  diffuse 111.  LEPTOLOMA. 

lOb.  Fruit    chartaceous-indurate,    rigid 14 

14a.  Spikelets  placed  with  the  back  of  the  fruit  turned  away  from 

the  rachis  of  the  racemes,  usually  single  (not  in  pairs) 15 

15a.  First  glume  and  the  rachilla  joint  forming  a  swollen  ring- 
like  callus  below  the  spikelet 113.  ERIOCHLOA. 

15b.  First  glume   present  or   wanting,   not   forming  a    ringlike 

callus  below  the   spikelet 16 

16a.  First  glume  present ;  racemes  racemose  along  the  main 

axis , 114.  BRACHIARIA. 

16b.  First  glume  wanting ;  racemes  digitate  or  subdigitate. 

115.  AXONOPUS. 
14b.  Spikelets  placed  with  the  back  of  the  fruit  turned  toward  the 

rachis  of  the  spikelike  racemes,  or  pedicellate  in  panicles 17 

17a.  Fruit  long-acuminate;  both  glumes  wanting-  116.  REIMAROCHLOA. 

17b.  Fruit  not  long-acuminate,  at  least  one  glume  present 18 

ISa.  First  glume  typically  wanting;  spikelets  plano-convex, 

subsessile  in  spikelike  racemes 117.  PASPALUM. 

ISb.  First  glume  present ;  spikelets  usually  in  panicles 19 

19a.  Second  glume  inflated-saccate,  this  and  the  sterile 
lemma  much  exceeding  the  stipitate  fruit. 

120.  SACCIOLEPIS. 

19b.  Second  glume  not  inflated-saccate 20 

20a.  Culms   woody  and  bamboolike;    fruit   with   a 

tuft  of  down  at  the  apex 119.  LASIACIS. 

20b.  Culms  herbaceous  ;  no  tuft  of  down  at  the  apex 

of  the  fruit 118.  PANICUM. 

TRIBE  13,  ANDROPOGONEAE. 

Spikelets  in  pairs  along  a  rachis,  the  usual  arrangement  being 
one  of  the  pair  sessile  and  fertile,  the  other  pedicellate  and  staminate 
or  neuter,  or  rarely  wanting,  only  the  pedicel  present ;  fertile  spike- 
let  consisting  of  one  perfect  terminal  floret  and,  below  this,  a  stami- 
nate or  neuter  floret,  the  lemmas  thin  or  hyaline,  and  two  awnless 
glumes,  one  or  usually  both  firm  or  indurate. 

A  large  tribe,  confined  mostly  to  warm  regions.  The  rachis  is 
usually  jointed,  disarticulating  at  maturity,  with  the  spikelets  at- 
tached. In  a  few  genera  it  is  thickened.  Sometimes  the  racemes  are 
shortened  to  1  or  2  joints  and  borne  on  branches,  the  whole  forming  a 
panicle  (as  in  Holcus  and  Sorghastrum)  instead  of  a  series  of 
racemes.  In  a  few  genera  the  spikelets  of  the  pair  are  alike.  In 
Traclwpogon  the  fertile  spikelet  is  pedicellate  and  the  sterile  one 
nearly  sessile. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  21 

Key  to  the  genera  of  Andropogoneae. 

la.  Spikelets  all  perfect,  surrounded  by  a  copious  tuft  of  soft  hairs 2 

2a.  llacliis  continuous,  the  spikelets  falling ;  spikelets  of  the  pair  un- 
equally pedicellate 3 

3a.  Racemes    in    a    narrow    spikelike    panicle,    spikelets    awn- 
less > 128.  IMPERATA. 

3b.  Racemes  in  a  broad  fan-shaped  panicle;   spikelets   awned. 

129.    MlSCANTHtJS. 

2b.  Rachis  breaking  up  into  joints  at  maturity  with  the  spikelets  at- 
tached ;  one  spikelet  sessile,  the  other  pedicellate 4 

4a.  Spikelets  awnless 130.  SACCHARUM. 

4b.  Spikelets    awned 131.  ERIANTHTJS. 

Ib.  Spikelets  unlike,  the  sessile  perfect,  the  pedicellate  sterile   (sessile 

spikelet  staminate,  pedicellate  spikelet  perfect  in  Trachypogon) 5 

5a.  Pedicel  thickened,  appressed  to  the  thickened  rachis  joint  (at 
least  parallel  to  it)  or  adnate  to  it;  spikelets  awnless,  ap- 
pressed to  the  joint G 

6a.  Rachis  joint  and  pedicel  adnate,  forming  a  short  flat  joint, 
this  sunken  in  the  open  side  of  the  globose  first  glume  of 
the  sessile  spikelet;  sterile  spikelet  conspicuous—  140.  RYTILIX. 
6b.  Rachis  joint  and  pedicel  distinct,   the   sessile   spikelet   ap- 
pressed to  them,  its  first  glume  lanceolate 7 

7a.  Racemes  subcylindric ;  rachis  joints  and  pedicels  glabrous, 
much  thicker  at  the  summit,  the  spikelets  sunken  in  the 

hollow  below ;  sterile  spikelet  rudimentary 130.  MANISURIS. 

7b.  Racemes  flat ;  rachis  joints  and  pedicels  woolly,  not  much 
thicker  at  the  summit;  sterile  spikelet  staminate  or  neu- 
ter  138.  ELYONURUS. 

5b.  Pedicel  not  thickened  (if  slightly  so  the  spikelets  awned),  neither 
appressed  nor  adnate  to  the  rachis  joint,  this  usually  slender ; 

spikelets  usually  awned ^ 8 

8a.  Fertile  spikelet  with  a  hairy-pointed  callus,  formed  of  the 

attached  supporting  rachis  joint  or  pedicel ;  awns  strong 9 

9a.  Racemes  reduced  to  a  single  joint,  long-peduncled  in  a 

simple  open  panicle 135.  RHAPHIS. 

9b.  Racemes  of  several  to  many  joints,  single 10 

lOa.  Primary  spikelet  subsessile,  sterile,  persistent  on 
the  continuous  axis  after  the  fall  of  the  fertile  pedi- 
cellate spikelet,  the  pedicel  forming  the  callus. 

137.  TRACHYPOGON. 

lOb.  Primary  spikelet  sessile,  fertile;  pedicellate  spike- 
let  sterile ;  lower  few  to  several  pairs  of  spikelets  all 

staminate  or  neuter 136.  HETEROPOGON. 

8b.  Fertile  spikelet  without  a  callus,  the  rachis  disarticulating 

immediately  below  the  spikelet ;  awns  slender 11 

lla.  Racemes  of  several  to  many  joints,  solitary,  digitate, 

or    aggregate 132.  ANDROPOGON. 

lib.  Racemes  reduced  to  one  or  few  joints,  these  mostly 

peduncled  in  a  subsimple  or  compound  panicle 12 

12a.  Pedicellate  spikelets  staminate 133.  HOLCUS. 

12b.  Pedicellate  spikelets  wanting,  the  pedicel  only 
present 134.  SORGHASTRUM. 


BULLETIN  772,  XT.   S.   DEPARTMENT  OF  AGRICULTURE. 
TRIBE  14,  TEIPSACEAE. 

celets  unisexual,  the  staminate  in  pairs,  or  sometimes  in  threes 
2-flowered,  the  pistillate  usually  single,  2-flowered,  the  lower  floret 
sterile,  imbedded  in  hollows  of  the  thickened  articulate  axis  and  fall- 
ing attached  to  the  joints,  or  inclosed  in  a  thickened  involucre  or 
sheath  or,  in  Zea,  crowded  in  rows  on  a  thickened  axis  (cob) ;  glumes 
membranaceous  or  thick  and  rigid,  awnless;  lemmas  and  palea 
hyaline,  awnless.  Plants  monoecious. 

This  small  tribe  of  seven  genera  is  scarcely  more  than  a  subtribe 
of  Andropogoneae.  It  is  also  known  as  Maydeae. 

Key  to  the  genera  of  Tripsaceae. 

la.  Staminate  and  pistillate  spikelets  in  separate  inflorescences,  the  first 

in  a  terminal  tassel,  the  second  in  the  axils  of  the  leaves 2 

2a.  Pistillate  spikes  distinct,  the  spikelets  embedded .  in  the  hardened 

rachis,  this  disarticulating  at  maturity 142.  ETJCHLAENA. 

2b.  Pistillate  spikes  grown  together  forming  an  ear.  the  grains  at 

maturity  much  exceeding  the  glumes 143.  ZEA. 

Ib.  S-taminate  and  pistillate  spikelets  in  separate  portions  of  the  same 

spike,  the  pistillate  below 3 

3a.  Spikes  short,  the  1  or  2  flowered  pistillate  portion  inclosed  in 

a  beadlike  sheathing  bract 144.  Coix. 

3b.  Spikes  many-flowered,  the  pistillate  portion  breaking  up  into 

several  1-seeded  joints;  no  beadlike  sheathing  bract 141.  TEIPSACUM. 

DESCRIPTIONS  OF  THE  GENERA. 

1.  BAMBOSEAE,  THE  BAMBOO  TRIBE. 

1.  ARTJNDINARIA  Michx. 

Spikelets  few  to  many  flowered,  large,  compressed,  the  rachilla 
disarticulating  above  the  glumes  and  between  the  florets ;  glumes  un- 
.equal,  shorter  than  the  lemmas,  the  first  sometimes  wanting ;  lemmas 
acute  or  acuminate  or  mucroiiate,  faintly  many-nerved;  palea  about 
as  long  as  the  lemma,  prominently  2-keeled. 

Shrubs  or  tall  reeds,  with  woody  perennial  branching  culms,  flat 
blades  with  petioles  articulate  with  the  sheaths,  and  loose  racemes 
or  panicles.  Species  about  25,  in  the  Tropics  of  both  hemispheres; 
2  species  in  the  southeastern  United  States. 

Type  species:  Arnndinarin  macrosperma  Michx. 

Arundinaria  Michx.,  Fl.  Bor.  Amer.  1 :  73.     1803.     One  species  described. 

Miegin  Pers.,  Syn.  PI.  1:101.  1805.  A  single  species,  based  on  Arundinaria 
macrosperma  Michx.,  is  included. 

Macronax  Raf.,  Med.  Repos.  ser.  2.  5:  353.  1808.  Based  on  "The  Arundi- 
naria of  Michaux." 

Our  two  species,  Anmdinaria  tecta  (Walt.)  Muhl.  (fig.  1)  and  A. 
macrosperma  (PL  I),  are  the  only  native  representatives  of  the  tropi- 
cal tribe  Bamboseae,  or  Bambuseae,  the  bamboos.  Our  species  are 
known,  respectively,  as  small  and  large  cane.  Both  flower  infre- 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE 


LARGE  CANE  (ARUNDINARIA  MACROSPERMA).     INFLORESCENCE,  LEAVES,  FLORETS, 

AND  RIPE  GRAINS. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  II, 


MEADOW  FESCUE  (FESTUCA  ELATIOR)  IN  FLOWER. 


GENERA  OF   GRASSES  OF  THE   UNITED  STATES.  23 


FIG.  1. — Small  cane,  Arundinaria  tccta.     Flowering  shoot  and  leafy  branch,   X    a  ;  spike- 
let  and  floret,   X   2. 


24  BULLETIN   772,   U.    S.   DEPARTMENT   OF   AGRICULTURE. 

quently.  The  first  is  rarely  over  G  feet  tall,  with  drooping  blades^ 
the  inflorescence  on  leafless  or  nearly  leafless  shoots  from  the  base  of 
the  plant.  This  is  found  from  Maryland  southward.  The  other 
species  grows  to  a  height  of  as  much  as  25  or  30  feet  and  forms,  in 
the  alluvial  river  bottoms  of  the  Southern  States,  dense  thickets 
called  canebrakes.  The  racemes  are  borne  on  leafy  branches,  the 
species  flowering  less  frequently  than  the  small  cane. 

Stock  are  fond  of  the  young  plants  and  of  the  leaves  and  seeds,  and 
both  species  furnish  much  forage  in  localities  where  they  are  abun- 
dant. The  young  shoots  are  sometimes  used  as  a  potherb.  The 
stems  or  culms  of  the  large  cane  are  used  for  fishing  rods,  pipestems, 
baskets,  mats,  light  scaffolding,  and  for  a  variety  of  other  purposes. 

2.  FESTUCEAE,  THE  FESCUE  TRIBE. 

2.  BROMTJS  L.,  the  brume-grasses. 

.  Spikelets  several  to  many  flowered,  the  rachilla  disarticulating 
above  the  glumes  and  between  the  florets ;  glumes  unequal,  acute,  the 
first  1  to  3  nerved,  the  second  usually  3  to  5  nerved ;  lemmas  convex 
on  the  back  or  keeled,  5  to  9  nerved,  2-toothed  at  the  apex,  awnless  or 
usually  awned  from  between  the  teeth;  palea  usually  shorter  than 
the  lemma. 

Annual  or  perennial,  low  or  rather  tall  grasses,  with  closed  sheaths, 
flat  blades,  and  open  or  contracted  panicles  of  large  spikelets.  Species 
about  100,  in  temperate  regions;  about  43  species  in  the  United 
States,  of  which  -IT  are  introductions,  mostly  from  Europe. 

Type  species:  Bromus  sccalinus  L. 

Bronras  L.,  Sp.  PI.  76,  1753 ;  Gen.  PI.,  eel.  5,  33.  1754.  Linnaeus  describes  11 
species,  all  but  the  last  2  of  which  are  still  retained  in  the  genus.  The  cita- 
tion given  after  Brornus  in  the  Genera  I'lantarum  is  "Mont.  32."  This"  refers 
to  figure  32  in  the  plate  accompanying  Monti's  Catalog!  Stirpium  Agri  Bononiensis 
Prodromus,  published  in  1719.  This  figure  represents  a  spikelet  of  Bromus 
secalinus,  or  of  a  closely  allied  species.  As  Brotnu*  sct-uH-mis  is  the  first  species 
described  in  the  Species  Plantarum  and  was  described  in  the  flora  of  Sweden, 
this  species  is  chosen  as  the  type. 

Ceratochloa  Beauv.,  Ess.  Agrost.  75,  pi.  15,  f.  7.  1812.  A  single  species  in- 
cluded. Festuca  unioloides  Willd.,  which  is  the  basis  of  Bromus  it mol aides 
(Willd.)  H.  B.  K. 

Zerna  Panz.,  Denkschr.  Baier.  Akad.  Wiss.  Miiench.  4:  296.  1813.  (Ideen 
Gatt.  Graser  46,  pi.  11,  f.  3.)  Eleven  species  are  included.  Bromus  stcrilis 
L.,  the  one  figured,  is  taken  as  the  type. 

Serrafalcus  Part.,  Rar.  PI.  Sic.  2:  14.  1840.  Six  species  are  included.  Bro- 
mus rac-cmosus  L.,  on  which  the  first  species  is  based,  is  taken  as  the  type. 

Forasaccus  Bubani,  Fl.  Pyren.  4 :  380.  1901.  Proposed  for  Bromus  L.,  not 
Bromus  of  the  ancients,  which  is  said  to  be  wild  oats. 

The  section  Ceratochloa  has  large  compressed  spikelets  with  com- 
pressed-keeled glumes  and  lemmas.  One  species,  Bromus  unioloides 
(Willd.)  H.  B.  K.,  is  cultivated  as  a  forage  grass  under  the  name 
of  rescue  grass  or  Schrader's  brome-grass.  This  is  an  annual  or  bi- 
ennial grass  1  to  2  feet  tall,  with  pubescent  sheaths  and  narrow  pani- 
cles of  smooth  spikelets  as  much  as  an  inch  long,  the  lemmas  acumi- 


GENERA  OF  GRASSES   OF  THE   UNITED  STATES.  25 

nate  or  awn-tipped.  Rescue  grass  is  a  native  of  South  America  and 
is  cultivated  occasionally  in  our  Southern  States  for  winter  forage. 
The  other  species  of  this  section  are  natives  of  the  western  half  of 
the  United  States.  They  are  all  perennials  and  have  large  awned 
spikelets.  Bromus  carinatus  Hook,  and  Am.  and  B.  marginatus 
Nees  are  common  on  the  Pacific  coast.  They  have  pubescent  or 
scabrous  spikelets,  the  first  with  an  awn  longer  than  the  lemma,  the 
second  with  an  awn  shorter  than  the  lemma.  Bromus  carinatus  often 
appears  like  an  annual,  flowering  the  first  year. 

The  species  of  Bromus  in  which  the  spikelets  are  not  compressed- 
keeled  fall  into  two  rather  well-marked  groups,  perennials  and  an- 
nuals. The  most  important  species  of  the  first  group  is  Bromus 
inermis  Leyss.,  a  European  species  known  also  as  awnless  brome- 
grass,  Hungarian  brome-grass,  smooth  brome-grass,  and  brome-grass. 
It  is  erect,  2  to  3  feet  tall,  with  creeping  rhizomes  and  narrow,  many- 
flowered  panicles  with  erect  or  ascending  branches  and  smooth  nar- 
row spikelets  about  an  inch  long,  the  lemmas  acute,  awnless,  or  nearly 
so.  Awnless  brome-grass  is  cultivated  for  hay  and  pasture  in  the 
northern  portion  of  the  Great  Plains  from  northern  Kansas  to 
Minnesota  and  Montana.  It  is  more  drought  resistant  than  timothy 
and  in  the  region  mentioned  can  be  grown  farther  west  than  that 
species,  but  does  not  thrive  south  of  central  Kansas.  All  the  other 
perennial  species  are  natives  except  B.  erectus,  occasionally  intro- 
duced from  Europe,  and  all  have  distinctly  awned  lemmas.  Bromus 
purgans  L.  is  a  common  woodland  species  in  the  Eastern  States. 
This  has  an  open  drooping  panicle  with  nearly  terete  spikelets,  the 
lemmas  pubescent  over  the  back.  The  closely  allied  and  equally  com- 
mon B.  ciliatus  L.  (fig.  2)  differs  in  having  lemmas  glabrous  on  the 
back  and  pubescent  on  the  margins  only.  Several  species  are  found 
in  the  Western  States,  B.  porteri  (Coult.)  Nash,  with  close  drooping 
panicle  and  softly  pubescent  spikelets,  being  common  in  the  Rocky 
Mountains. 

The  group  of  annuals  includes  weedy  species  introduced  mostly 
from  Europe.  The  best  known  of  these  in  the  Eastern  States  is 
Bromus  seealinus  (fig.  3),  chess  or  cheat,  a  weed  of  waste  places  and 
sometimes  infesting  grain  fields.  Formerly  it  was  believed  by  the 
credulous  that  under  certain  conditions  wheat  changed  into  chess. 
Chess  in  a  wheat  field  is  due  to  chess  seed  in  the  soil  or  to  chess  seed 
in  the  wheat  sown.  Chess  is  a  smooth  grass  1  to  3  feet  tall,  with  flat 
blades  and  open  duooping  panicles  of  smooth  turgid  spikelets,  the 
lemmas  broad  and  inrolled  above,  the  awn  about  as  long  as  the  lemma. 
Bromus  commutatus  Schrad.  differs  in  having  pubescent  sheaths. 

On  the  Pacific  coast  the  annual  species  of  Bromus  have  become 
conspicuous.  They  thrive  on  all  open  ground  at  lower  altitudes  in 


26  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  2. — Wild  brome-grass,  Bromus  ciliatus.     Plant,    X    i  ;  spikelet  and  floret,   X   5. 


GENEKA  OF   GRASSES   OF   THE   UNITED  STATES.  27 


FIG.  3. — Chess   (cheat),  Bromus  secalinus.     Plant,    X    2  ;  spikelet  and  floret,    X    5. 


28  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

spring  and  early  summer,  and  on  the  approach  of  the  summer  dry 
season  they  ripen  their  seed  and  turn  brown.  They  often  cover 
vast  areas  and  have  become  a  great  pest.  The  commonest  species  are 
B.  rub&ns  L.,  with  contracted  panicles  of  narrow  usually  purplish 
spikelets;  B.  hordeaceus  L.,  with  compact  panicles  of  short  turgid 
usually  pubescent  spikelets  like  those  of  B.  secodmus;  B.  villosus 
Forsk.,  with  open  rather  few-flowered  panicles  and  narrow  spike- 
lets  with  awns  as  much  as  2  inches  long;  and  B.  tectorum  L.  (fig.  4), 
a  rather  small  softly  pubescent  species,  with  drooping  panicles  of 
narrow  spikelets.  Bromws  trimi  Desv.,  found  chiefty  in  the  desert 
regions  of  California,  introduced  from  Chile,  is  peculiar  in  having 
a  bent  awn  twisted  below.  Bromus  arenarius  Labill.,  a  recent  intro- 
duction from  Australia,  is  becoming  common.  This  has  an  open 
panicle  with  capillary  curved  pedicels  and  short,  pubescent  spikelets. 

The  perennial  species  of  Bromus  are  important  forage  grasses  on 
the  mountain  ranges  of  the  Western  States.  The  annual  species  are 
good  forage  grasses  wThen  they  are  young,  but  they  are  rather  eva- 
nescent. The  fruits  of  B.  villosus.  and  B.  rubens  and  their  allies  are 
injurious  to  stock,  the  sharp-pointed  florets  working  their  way  into 
the  eyes  and  nostrils.  BromMs  secalmm  is  grown  for  hay  in  Wash- 
ington, in  Oregon,  and  in  Georgia. 

For  a  revision  of  the  species  of  Bromus  found  in  the  United  States, 
see  Shear,  U.  S.  Dept.  Agr.,  Div.  Agrost.  Bull.  23.  1900. 

3.  FESTUCA  L.,  the  fescue  grasses. 

Spikelets  few  to  several  flowered,  the  rachilla  disarticulating  above 
the  glumes  and  between  the  florets;  glumes  narrow,  acute,  unequal, 
the  first  sometimes  very  small;  lemmas  rounded  on  the  back,  mem- 
branaceous  or  somewhat  indurate,  5-nerved,  the  nerves  often  obscure, 
acute  or  rarely  obtuse,  awned  from  the  tip  or  rarely  from  a  minutely 
bifid  apex. 

Annual  or  perennial  low  or  rather  tall  grasses  of  varied  habit,  the 
spikelets  in  narrow  or  open  panicles.  Species  about  100,  in  the  tem- 
perate and  cool  regions;  about  40  species  in  the  United  States,  7  of 
which  are  introductions  from  Europe. 

Type  species:  Festuca  ovina  L. 

P'estuca  L.,  Sp.  PI.  73,  1753;  Gen.  PI.,  ed.  5,  33.  1754.  Linnaeus  describes  11 
species.  Festuca  ovina  is  chosen  as  the  type,  as  it  is  the  first  of  the  original 
species  that  is  economic  and  is  described  in  the  flora  of  Sweden.  Most  of  the 
original  species  are  still  retained  in  Festuca  but  F.  flecumbens  is  now  placed 
in  Sieglingia,  F.  fluitans  in  Panicularia,  and  F.  cristata  in  Koeleria  (.K. 
phleoides). 

Vulpia  Gmel.,  Fl.  Badens.  1:  8.  1805.  One  species,  V.  'myuros,  based  on 
Festuca  myuros  L.,  is  described,  and  two  species  of  Festuca  having  a  single 
stamen  are  mentioned  in  a  note.  Festuca  myuros  is  taken  as  the  type. 

Schedonorus  Beauv.,  Ess.  'Agrost.  99,  pi.  19,  f.  2.  1812.  The  first  of  the  25 
species  included  and  the  one  figured  is  "Bromus  elatior"  (L.)  KoeL,  based  on 
Festuca  elatior.  The  figure  shows  a  floret  with  a  short  awn  below  the  minutely 
bidentate  apex,  as  found  in  occasional  specimens  of  F.  elatior,  which  species  is 
taken  as  the  type. 


GENERA   OF   GRASSES   OF   THE    UNITED   STATES. 


29 


FIG.  4. — Downy  brome-grass,  Bromm  tectorum.     Plant,    X    J  ;  splkelet  and  floret,   X   5. 


30 


BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


Dasiola  Raf.,  Neogenyt.  4.  1825.  "  Type  Festuca  monandra  "  Ell.,  renamed 
D.  elliottea  Raf.  This  is  F.  scinrea  Nutt. 

Chloaninia  Raf., 
Neogenyt.  4.  1825. 
Two  species  are  in- 
cluded, Festuca  te- 
ncUtt  and  F.  liromoi- 
dcs.  The  first,  which 
is  F.  octo  flora  Walt., 
is  taken  as  the  type. 

Hesperochloa  (Pi- 
per) Rydb.,  Bull. 
Torrey  Club  39:  106. 
1912.  Based  on  Fes- 
tuca subgenus  Hes- 
perochloa Piper,  the 
type  and  only  species 
of  which  is  F.  confi.n-ix 
Vasey. 

Wasatchia  Jones, 
Contr.  West.  Bot.  14 : 
16.  1912.  A  single 
species  is  included, 
ir.  Jcinffii  (Watson) 
Jones,  based  on  Po<i 
kluyii  Watson,  which 
is  the  same  as  F.  con- 
finis  Vasey. 

Gnomonia  Lunell, 
Amer.  Midi.  Nat.  4: 
224.  1915.  A  new 
name  proposed  for 
Festuca  L.,  not  Do- 
donaeus,  1551. 

The  subgenus 
Yulpia,  including 
annuals  with  most- 
ly narrow  panicles 
and  floAvers  with 
but  one  stamen,  is 
represented  in  the 
United  States  by 
13  species,  2  of 
which,  Festuca 
inyuros  L.  and  F. 
ftromoidcs  L.,  are 
introductions 
from  Europe. 
Festuca  octojlora 
Walt.  (fig.  5), 
with  spikelets  usu- 
ally more  than 
5 -flowered  and 
hard  terete  gla- 
brous or  scabrous 
lemmas  with  no  scarious  margin,  is  common  throughout  the  United 
States.  Several  native  species  of  this  subgenus  are  found  on  the 
Pacific  coast. 


FIG.  5. — Festuca  octoflora. 


spikelet  and  floret, 


GENERA   OF   GRASSES   OF   THE   UNITED  STATES.  31 

The  subgenus  Hesperochloa  includes  a  single  species  Festuca 
confinis  Vasey,  a  stout  tufted  perennial  with  creeping  rhizomes,  firm 
flat  blades,  and  narrow  panicles  of  awnless  spikelets. 

The  remaining  species,  all  perennials,  are  placed  in  the  subgenus 
Eufestuca.  Mountain  bunch-grass  (F.  viridula  Vasey)  with  nar- 
row flat  or  loosely  involute  blades  and  awnless  spikelets  is  common 
in  the  subalpine  meadows  of  the  northwestern  mountains  where  it 
constitutes  an  important  part  of  the  forage.  Festv)ca  subulate  Trin., 
a  common  woodland  species  of  the  Northwestern  States,  has  flat  thin 
blades  and  very  open  panicles  of  long-awned  spikelets.  Much  re- 
sembling this  is  F.  sulmli flora  Scribn.,  which  is  peculiar  in  having 
a  stipelike  elongation  at  the  base  of  the  florets.  An  allied  Califor- 
nian  species,  F.  elmeri  Scribn.  and  Merr.^ias  spikelets  like  F.  subulata, 
but  the  awn  arises  between  the  two  minute  teeth  of  the  lemma.  Fes- 
tuca obtusa,  Spreng.  is  an  eastern  woodland  species  with  very  loose 
sparingly  'branched  panicle  and  few  awnless  spikelets.  The  largest 
species  of  the  genus  in  the  United  States  is  F.  calif omica  Vasey, 
found  in  dry  woods  of  western  California  and  Oregon.  This  grows 
in  large  tufts,  with  culms  as  much  as  5  feet  tall,  hard  flat  or  loosely 
involute  blades,  pilose  on  the  collar,  and  large  panicles. 

The  type  species,  Festuca  ovina,  is  the  representative  of  a  large 
group  of  varieties  or  closely  allied  species  in  Europe.  Festuca  omna 
itself  is  cultivated  as  a  lawn  or  pasture  grass  under  the  name  of 
sheep's  fescue.  It  is  a  tufted  grass  6  to  18  inches  tall  with  firm,  short, 
involute  blades,  crowded  at  the  base  of  the  slender  culms,  and  narrow 
panicles  of  short-awned  spikelets.  This  grass  is  used  in  mixtures 
for  sterile  or  stony  soil.  Three  allied  European  species  are  used  in 
the  same  way  but  especially  in  mixtures  for  lawns.  These  are  F. 
durmscula  L.,  hard  fescue  (a  species  rare  in  America),  with  blades 
about  1  mm.  broad;  F.  heterophyUa~Lsim.,  with  flat  stem  blades;  and 
F.  capillata  Lam.,  with  very  fine  blades  and  awnless  spikelets.  Eed 
fescue,  F.  rubra  L.  (fig.  6),  differs  in  the  loosely  tufted  culms  with 
decumbent  usually  red  bases.  This  is  native  in  both  Europe  and 
America.  Two  species  allied  to  F.  ovina  are  native  in  the  Western 
States  and  are  both  important  range  grasses.  These  are  F.  idahoensis 
Elmer  (F.  ingrata  (Hack.)  Kydb.),  blue  bunch-grass,  with  pale 
narrow  stiff  harshly  scabrous  blades  6  to  15  inches  long,  and  awned 
spikelets,  common  from  British  Columbia  to  Colorado  and  Cali- 
fornia ;  and  F.  arizonica  Vasey,  Arizona  fescue,  with  nearly  awnless 
spikelets,  found  in  northern  Arizona  and  southern  Utah. 

The  most  important  cultivated  species  of  the  genus  is  Festuca 
elatior  L..  meadow  fescue  (PI.  II ;  fig.  7) .  This  is  a  smooth  perennial, 
1  to  4  feet  high,  with  flat  blades  and  a  narrow  but  rather  loose  panicle 
1  to  8  inches  long,  the  awnless  spikelets  about  half  an  inch  long. 
Meadow  fescue  is  cultivated  for  hay  and  pasture  in  the  humid  region, 


32  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

especially  in  Tennessee,  Missouri,  and  eastern  Kansas.  There  are  two 
agricultural  varieties  of  this  species.  The  taller  form  with  larger 
more  open  panicle  is  distinguished  as  tall  fescue.  The  form  more 


FIG.  6. — Red  fescue,  Festuca  rubra.     Plant,   X   1  ;  spikelet  and  floret,  x   5. 


GENERA  OF   GRASSES  OF  THE   UNITED  STATES.  33 


FIG.  7. — Meadow  fescue,  Festuca  elatior.     Plant,   X    \  ;  spikelet  and  floret,   X   5. 

commonly  cultivated,  usually  called  meadow  fescue,  is  2  or  3  feet 
tall  and  has  a  nearly  simple  panicle,  sometimes  racemose  above  and 
slightly  branched  at  the  base.    In  eastern  Kansas  the  incorrect  name 
English  bluegrass  is  sometimes  applied  to  this  species, 
97769°— 19— Bull.  772 3 


34  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

For  a  revision  of  the  species  of  Festuca  found  in  North  America, 
see  Piper,  Contr.  U.  S.  Nat.  Herb.  10 : 1-48,  pi.  1-15.     1906. 


Scleropoa  Griseb.,  Spicil.  Fl.  Kumel.  2 :  431.    1844. 

The  one  species.  Scleropoa  rigida  (L.)  Griseb.,  a  native  of  southern 
Europe,  is  sparingly  introduced  in  the  United  States,  mostly  as  a 
ballast  plant.  It  is  a  low  annual  with  racemes  of  spikelets  resembling 
those  of  Puccinellia.  The  glumes  are  1-nerved,  the  lemmas  convex 
on  the  back  and  obscurely  nerved.  The  type  is  Poa  rigida  L. 


Brachypodium  Beauv.,  Ess.  Agrost.  100,  155.    1812. 

One  species,  Brachypodium  distackyon  (L.)  Beauv.,  of  Europe, 
has  been  found  on  ballast  at  Portland,  Oreg.,  and  Camden,  N.  J.  It 
is  a  low  tufted  annual,  with  stiff  culms  ending  in  a  raceme  of  1  to 
few  short-pediceled,  many-flowered  cylindric  spikelets,  the  awnecl 
lemmas  rounded  on  the  back,  the  paleas  stiffly  ciliate  on  the  keels. 

4.  PANICULARIA  Heister. 
(Glyceria  R.  Br.) 

Spikelets  few  to  many  flowered,  subterete  or  slightly  compressed, 
the  rachilla  disarticulating  above  the  glumes  and  between  the  florets ; 
glumes  unequal,  short,  obtuse  or  acute,  usually  scarious,  mostly  1- 
nerved ;  lemmas  broad,  convex  on  the  back,  firm,  usually  obtuse,  awn- 
less,  scarious  at  the  apex,  5  to  9  nerved,  the  nerves  parallel,  usually 
prominent. 

Usually  tall  aquatic  or  marsh  grasses,  with  flat  blades,  closed  or 
partly  closed  sheaths,  and  open  or  contracted  panicles.  Species  about 
35,  in  the  temperate  regions  of  both  hemispheres;  16  species  in  the 
United  States. 

Type  species :  Poa  aquatica  L. 

Panicularia  Heister ;  Fabr.,  Enum.  PI.  Hort.  Helmst.,  ed.  2,  373.  1763.  The 
genus  is  based  on  the  species  that  Linnaeus  named  Poa  aquatica. 

Festucaria  Heister;  Fabr.,  Enum.  PI.  Hort.  Helmst.,  ed.  2,  374.  The 
genus  is  based  on  the  species  that  Linnaeus  named  Festuca  fluitans. 

Glyceria  R.  Br.,  Prodr.  Fl.  Nov.  Holl.  179.    1810.    Based  on  Festuca  fluitans  L. 

Nevroloma  Raf.,  Journ.  de  Phys.  89:  106.  1819.  "Type,  le  Briza  canadensis 
de  Michaux."  This  is  Panicularia  canadensis. 

Our  species  are  divided  into  two  rather  well  marked  groups.  One 
group,  consisting  of  five  species,  has  linear  spikelets  usually  as  much 
as  1  cm.  long.  These  species  are  represented  by  Panicularia  fluitans, 
the  type  of  Festucaria  and  Glyceria.  The  group  to  which  P.  aquatica 
belongs  has  ovate  or  oblong  spikelets  usually  not  over  5  mm.  long. 

The  commonest  species  is  Panicularia  nervata  (Willd.)  Kuntze 
(fig.  8),  with  small  prominently  7-nerved  spikelets  in  open  panicles. 
Panicularia  canadensis  (Michx.)  Kuntze  has  larger  less  prominently 


GENERA  OF   GRASSES  OF  THE   UNITED  STATES. 


35 


FIG.  8.— Manna  grass,  Panicularia  nervata.     Plant,   x   J  ;  spikelet  and  floret,   X  5. 


36  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

nerved  spikelets.  Panicularia  grandis  (S.  Wats.)  Nash  has  very  large 
panicles  of  oblong  spikelets,  the  lemmas  prominently  7-nerved.  Pani- 
cula?*ia  pauciftora  (Presl)  Kuntze,  found  in  the  western  mountains, 
has  5-nerved  lemmas  and  rather  small  panicles. 

The  species  are  sometimes  called  manna  grass  and  fowl  meadow 
grass.  They  are  all  excellent  forage  grasses,  but  usually  form  no 
very  important  part  of  the  grazing  because  they  are  limited  to 
swampy  regions.  Hydrocyanic  acid  has  been  found  in  Pq$4cularia 
nervata,  and  some  cases  of  cattle  poisoning  have  been  ascribed  to  it.1 

5.  PLEUROPOGON  R.  Br. 

Spikelets  several  to  many  flowered,  linear,  the  rachilla  disarticu- 
lating above  the  glumes  and  between  the  florets;  glumes  unequal, 
membranaceous  or  subhyaline,  scarious  at  the  somewhat  lacerate  tip, 
the  first  1-nerved,  the  second  obscurely  3-nerved;  lemmas  membra- 
naceous, 7-nerved,  with  a  round  indurate  callus  at  base,  the  apex  en- 
tire or  2-toothed,  the  midnerve  extending  into  a  short  mucro  or  into 
an  awn ;  palea  2-keeled,  the  keels  winged  on  the  lower  half. 

Soft  annuals  or  perennials,  with  flat  blades  and  loose  racemes  of 
rather  large  spikelets.  Species  three,  one  in  the  arctic  region  and 
two  on  the  Pacific  coast  of  the  United  States. 

Type  species :  Plctiropogon  sabinii  R.  Br. 

Pleuropogon  R.  Br.,  Suppl.  App.  Parry's  Voy.  189,  pi.  D.  1823.  A  single 
species,  described  and  figured. 

Lophochlaena  Nees,  in  Taylor,  Ann.  Nat.  Hist.  1:  283.  1838.  Type  L.  cali- 
fornica,  the  only  species  described. 

Our  species  are  found  in  bogs  and  wet  meadows.  One,  Pleu- 
ropogon calif  omicus  (Nees)  Benth.  (fig.  9), an  annual  with  ascending 
spikelets,  is  confined  to  California.  The  other,  P.  refractus  (Gray) 
Benth.,  a  perennial  with  drooping  spikelets,  is  found  from  northern 
California  to  Washington.  They  are  palatable  grasses,  but  occur  too 
infrequently  to  be  of  economic  value. 

6.  PUCCINELLIA  Parl. 

Spikelets  several-flowered,  usually  terete  or  only  slightly  flattened, 
the  rachilla  disarticulating  above  the  glumes  and  between  the  florets ; 
glumes  unequal,  shorter  than  the  first  lemma,  obtuse  or  acute,  rather 
firm,  often  scarious  at  the  tip,  the  first  1-nerved  or  sometimes 
3-nerved,  the  second  3-nerved;  lemmas  usually  firm,  rounded  on  the 
back,  obtuse  or  acute,  rarely  acuminate,  usually  scarious  and  often 
erose  at  the  tip,  glabrous  or  puberulent  toward  the  base,  5-nerved, 
the  nerves  parallel,  obscure  or  indistinct,  rarely  rather  prominent; 
palea  about  as  long  as  the  lemma  or  somewhat  shorter. 

Annual,  or  usually  perennial,  low  pale  smooth  cespitose  grasses, 
with  narrow  or  open  panicles.  Species  about  25,  mostly  along  coasts 

1  Alsberg  and  Black.     Journ.  Biol.  Chcm.  21 :  601.     1915. 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES.  37 


Fie.  V.—Pleuropogon  caMfornicus.     Plant,    X    i;   spikelet,    X    3;   floret,    X   5. 


38  BULLETIN   772,   IT.   S.   DEPARTMENT  OF  AGRICULTURE. 

and  on  interior  alkali  soil  of  the  cool  and  arctic  regions  of  the 
Northern  Hemisphere;  about  12  species  in  the  United  States,  on 
the  Atlantic  coast  south  to  Delaware,  on  the  Pacific  coast  south  to 
Point  Beyes,  and  in  the  western  interior  south  to  New  Mexico. 

Type  species:  Poa  distans  L. 

Puccinellia  Parl.,  Fl.  Ital.  1:  366.  1848.  Parlntore  describes  4  species,  P. 
distans  (L.)  Parl.,  P.  festvcaeformis  (Host)  Parl.,  P.  gussonii  Parl.,  and  P. 
maritima  (Huds.)  Parl.  The  first  is  selected  as  the  type. 

Atropis  Rupr.,  in  Griseb.  in  Ledeb.  Fl.  Ross.  4:  388.  1853.  Based  upon  Poa, 
section  Atropis  Rupr.,1  of  which  the  type  and  only  species  is  Poa  distans  L. 

Puccinellia  differs  from  Poa  in  the  rounded  lemmas  with  indistinct 
and  parallel  nerves.  The  species  are  mostly  confined  to  the  brackish 
marshes  of  the  coast.  One  species,  Puccinellia  nuttalliana  (Schult,") 
Hitchc.  (P.  airoides  (Nutt.)  Wats,  and  Coult.)  (fig.  10),  is  common 
in  alkaline  soils  of  the  interior  from  Minnesota  to  Washington  and 
south  to  New  Mexico.  This  species  furnishes  considerable  forage 
where  it  is  common. 

7.  FLTJMINEA  Fries. 
(Scolochloa  Link.) 

Spikelets  3  to  4  flowered,  the  rachilla  disarticulating  above  the 
glumes  and  between  the  florets;  glumes  nearly  equal,  somewhat  scari- 
ous  and  lacerate  at  summit,  the  first  3-nerved,  the  second  5-nerved, 
about  as  long  as  the  first  lemma ;  lemmas  firm,  rounded  on  the  back, 
villous  on  the  callus,  7-nerved,  the  nerves  rather  faint  and  unequal, 
extending  into  a  scarious  lacerate  apex;  palea  narrow,  flat,  about 
as  long  as  the  lemma. 

Tall  perennials,  with  succulent  rhizomes,  flat  blades,  and  spread- 
ing panicles.  Species  two,  one  in  eastern  Siberia,  the  other  in  north- 
ern Eurasia  and  northern  North  America,  extending  south  to  Iowa. 

Type  species :  Festuca  borcalis  Mert.  and  Koch. 

Scolochloa  Link,  Hort.  Berol.  1:  136,  1827,  not  Scolochloa  Mert.  and  Koch. 
1823.  Based  on  Arundo  festucacea  Willd.  (Scolochloa  festucacea  Link),  the 
only  species  described.  Scolochloa  Mert.  and  Koch  is  based  on  Arundo  dona.r  L. 

Fluminea  Fries,  Summa  Veg.  Scand.  247.  1846.  Based  on  Festuca  boreal  IK. 
A  single  species  is  included,  its  name  being  given  as  "  Festuca  boreulis 
or  Fluminea  arundinucea"  This  is  the  same  as  Scolochloa  festucacea. 

Our  single  species,  Fluminea  festucacea  (Willd.)  Hitchc.  (Arundo 
festucacea  Willd.,  Graphephorum  festucaceum,  Gray,  ScoloMoa  fes- 
tucacea (Willd.)  Link)  (fig.  11),  is  a  marsh  grass  found  from  Iowa 
and  Minnesota  northward.  It  has  some  value  for  forage  and  is  often 
a  constituent  of  marsh  hay. 

8.  POA  L.,  the  bluegrasses. 

Spikelets  2  to  several  flowered,  the  rachilla  disarticulating  above 
the  glumes  and  between  the  florets,  the  uppermost  floret  reduced  or 
rudimentary;  glumes  acute,  keeled,  somewhat  unequal,  the  first 

iBeitr.  Pflanzenk.  Russ.  Reich.  2:  81.     1845  (Fl.  Samoj.  Cis.). 


GENERA  OF  GRASSES   OF  THE   UNITED  STATES.  39 


FIG.  W.—Puccinellia  nuttalliana.     Plant,   X    i  ;  spikelet  and  floret,   X   5. 


40  BULLETIN  772,  TJ.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  ll.—Fluminea  festucacea.    Plant,   X   i  ;  spikelet  and  floret,   X   5. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  41 

1-nerved,  the  second  usually  3-nerved ;  lemmas  somewhat  keeled,  acute 
or  acutish,  awnless,  membranaceous?  often  somewhat  scarious  at  the 
tip,  5-nerved,  the  nerves  sometimes  pubescent. 

Annual,  or  usually  perennial,  species  of  low  or  rather  tall  grasses, 
with  spikelets  in  open  or  contracted  panicles,  the  narrow  blades 
flat  or  folded,  ending  in  a  navicular  point.  Species  probably  over 
200,  in  the  temperate  and  cool  regions ;  about  90  in  the  United  States, 
being  especially  numerous  in  the  western  mountains. 

Type  species :  Poa  pratensi*  L. 

Poa  L.,  Sp.  PI.  67,  1753;  Gen.  PI.,  ed.  5,  31.  1754.  Linnaeus  describes  17 
species,  8  of  which  are  still  retained  in  the  genus.  Poa  pratensis  is  chosen  as  the 
type  because  it  is  an  important  economic  species  and  because  it  is  among  the 
species  described  under  Poa  in  the  Flora  Lapponica.  The  first  of  the  original 
species,  /'.  <H]  mi  lira,  is  now  referred  to  Panicularia  ;  P.  flava  to  Triodia  ;  P.  pilosa, 
P.  amaMUs,  P.  eragrostis,  P.  capillaris,  and  P.  tenella  to  Eragrostis;  P.  mala- 
barica  to  (Vnlothecn  ;  7*.  cHinensis  to  Leptochloa. 

Paneion  Lunell,  Amer.  Midi.  Nat.  4 :  221.  1915.  Proposed  for  Poa  L.,  the  word 
poa  being  a  Greek  common  noun,  meaning  herb,  the  author  regarding  it  "unfit 
as  [a]  generic  name." 

The  base  of  the  lemma  sometimes  bears  a  tuft  of  loose  cottony  hairs. 
A  group  of  western  species,  including  Poa  scabrella,  (Thurb.)  Benth. 
of  California  (fig.  12),  P.  nevadensis  Yasey  of  the  Great  Basin,  and 
P.  sandberyii  Vasey  of  the  northern  Rocky  Mountain  region,  have 
narrow,  nearly  terete  spikelets,  in  narrow  panicles,  the  lemmas 
rounded  on  the  back,  glabrous,  scabrous  or  minutely  pubescent  below. 
Several  species,  such  as  mutton  grass  (P.  fendleriana  (Steud.)  Vasey) 
and  its  allies,  P.  douglasii  Nees,  and  P.  arachnifera  Torr.,  are 
dioacious.  A  few  species,  such  as  P.  annua  L.,  P.  ~bigelovii  Vasey  and 
Scribn.  of  Arizona,  P.  howellii  Vasey  and  Scribn.,  and  P.  bolanderi 
Vasey  of  California,  are  annual.  Some  of  the  perennial  species, 
such  as  P.  scabrella,  are  bunch  grasses,  and  some  like  P.  pratensis  and 
P.  compressa  produce  creeping  rhizomes.  Poa  macrantha  Vasey,  a 
dioacious  sand-dune  grass  of  Oregon,  has  spikelets  as  much  as  half 
an  inch  long. 

The  bluegrasses  are  of  great  importance  because  of  their  forage 
value,  some  species  being  cultivated  for  pasture  and  others  forming 
a  large  part  of  the  forage  on  the  mountain  meadows  of  the  West. 

The  most  important  species  of  the  genus  is  Poa  pratensis  L.  (PL 
III ;  fig.  13)  commonly  known  as  Kentucky  bluegrass,  or  simply  blue- 
grass.  This  is  a  smooth  perennial,  with  creeping  rhizomes,  erect 
culms  1  to  3  feet  high,  soft  flat  or  folded  blades  and  open  pyramidal 
panicles  2  to  4  inches  long,  the  lower  branches  in  a  whorl  of  usually  5, 
the  spikelets  mostly  4  to  6  flowered,  the  florets  cobwebby  at  base,  the 
keel  and  marginal  nerves  villous.  Bluegrass  is  a  native  of  Europe, 
but  is  widely  naturalized  in  the  cooler  parts  of  this  country  and  is 
cultivated  for  pasture  and  for  lawns.  It  is  the  standard  pasture  grass 
in  the  humid  regions  of  the  United  States  where  the  soil  contains 
plenty  of  lime. 


42  BULLETIN  772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  12.—  Poo,  scabrella.     Plant,   X   \  ;  spikelet  and  floret,   x  5. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  III. 


KENTUCKY  BLUEGRASS  (POA  PRATENSIS). 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  IV. 


CANADA  BLUEGRASS  (POA  COMPRESSA)  IN  FLOWER. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  V. 


ANNUAL  BLUEGRASS  (PDA  ANNUA). 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  VI. 


"£ 


* 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES.  43 


FlG    !3 Bluegrass,  Poa  pratensis.     Plant,   X    I  ;  spikelet  and  floret,   X  5. 


44  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

The  name  Kentucky  bluegrass  has  been  used  because  in  Kentucky 
the  bluegrass  pastures  have  been  a  prominent  feature  of  the  agricul- 
ture of  the  State.  In  the  northern  portion  of  its  range  it  is  usually 
called  June-grass.  Bluegrass  flourishes  as  far  west  as  eastern  Ne- 
braska and  as  far  south  as  Virginia  and  in  the  mountains  to  northern 
Alabama.  In  the  valleys  of  the  western  mountains  and  in  the  humid 
region  of  the  Pacific  coast,  from  northern  California  to  British 
Columbia,  bluegrass  is  the  common  pasture  grass.  In  the  regions 
where  bluegrass  is  used  for  pasture  it  is  the  standard  lawn  grass. 
By  liming  the  soil  and  by  artificial  watering  bluegrass  may  be  grown 
for  lawns  beyond  the  limits  outlined  above,  but  it  can  not  be  made 
to  thrive  in  the  warmer  parts  of  the  Southern  States  or  in  the  arid 
regions  of  the  Southwest. 

Poa  compressa  L.  (PL  IV),  cultivated  under  the  name  of  Canada 
bluegrass,  is  of  some  commercial  importance,  being  grown  in  the 
region  that  is  adapted  to  the  growth  of  Kentucky  bluegrass,  but  it 
is  used  chiefly  on  sterile  sandy  or  clay  soils  where  the  latter  species 
does  not  thrive.  Canada  bluegrass  differs  from  Kentucky  bluegrass 
in  its  blue-green  color,  distinctly  compressed  stems,  and  narrow  less- 
branched  panicles.  It  produces  abundant  rhizomes  that  throw  up 
numerous  scattered  stems,  mostly  6  to  15  inches  tall,  these  being 
usually  solitary  rather  than  tufted.  On  account  of  its  wiry,  com- 
pressed stems  it  is  called  in  some  localities  wire-grass  and  flat-stem. 

Two  other  species  of  Poa  occasionally  grown  but  of  little  agricul- 
tural importance  are  Poa  trivialis  L.,  rough-stalked  meadow  grass,  a 
species  lacking  rhizomes,  but  resembling  P.  pratensis  in  its  panicle, 
distinguished  easily  by  its  backwardly  roughened  sheaths;  and  Poa 
palustris  L.  (P.  triflora  Gilib.,  P.  serotina  Ehrh.)  known  to  seedsmen 
as  fowl  meadow  grass,  a  smooth,  rather  tall,  tufted  grass,  differing 
from  bluegrass  in  the  absence  of  rhizomes,  in  the  larger  more  open 
panicle,  and  in  the  smaller,  2  to  4  flowered  spikelets. 

Poa  arachnifera  Torr.,  Texas  bluegrass,  has  been  used  in  some  of  the 
Southern  States  as  a  winter  pasture  grass  and  as  a  lawn  grass.  It  is 
an  erect  dioecious  grass,  1  to  2  feet  high,  with  strong  rhizomes  and 
narrow  panicles,  2  to  4  inches  long,  the  staminate  spikelets  glabrous, 
the  pistillate  spikelets  with  a  copious  tuft  of  woolly  hairs  at  the  base 
of  the  florets.  Texas  bluegrass  is  a  native  of  Oklahoma  and  Texas. 

Poa  annua  L.,  annual  bluegrass  (PI.  V),  is  a  low,  soft,  light-green, 
annual  grass  that  is  frequently  found  as  a  weed  in  lawns  and  gardens. 
It  thrives  in  the  spring  or  even  in  the  winter  in  southerly  regions, 
forming  fine  light-green  patches,  which  die  out  later  in  the  season, 
leaving  unsightly  spots.  Poa  annua  is  a  native  of  Europe,  but  is 
widely  introduced  in  America. 

Several  species  are  important  range  grasses.  Malpais  bluegrass 
(Poa  scabrella],  a  bunch  grass,  with  slightly  roughened  sheaths  and 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  45 

narrow  panicles  of  cylindric  spikelets,  the  lemmas  pubescent  below,  is 
common  at  lower  altitudes  in  California.  Mutton  grass  (P.  fendleri- 
ana)  is  important  in  the  Southwest.  Little  bluegrass  (P.  sand- 
bergii),  differing  from  malpais  bluegrass  in  having  smooth  sheaths,  is 
common  at  medium  altitudes  (2,000  to  8,000  feet)  throughout  the 
Northwest. 

9.  BRIZA  L.,  the  quaking  grasses. 

Spikelets  several-flowered,  broad,  often  cordate,  the  florets  crowded 
and  spreading^  horizontally,  the  rachifla  glabrous,  disarticulating 
above  the  glumes  and  between  the  florets,  the  uppermost  floret  re- 
duced; glumes  about  equal,  broad,  papery-chartaceous,  with  scarious 
margins;  lemmas  papery,  broad,  with  scarious,  spreading  margins, 
cordate  at  base,  several-nerved,  the  nerves  often  obscure,  the  apex 
in  our  species  obtuse  or  acutish ;  palea  much  shorter  than  the  lemma. 

Annual  or  perennial,  low  grasses,  with  erect  culms,  flat  blades,  and 
usually  open,  showy  panicles,  the  pedicels  in  our  species  capillary, 
allowing  the  spikelets  to  vibrate  in  the  wind.  Species  about  20,  the 
greater  number  South  American.  The  three  species  found  in  the 
United  States  are  introductions  from  Europe  and  occur  here  as 
occasional  weeds  in  waste  places. 

Type  species :  Briza  media  L. 

Briza  L.,  Sp.  PI.  70,  1753;  Gen.  PI.,  ed.  5,  32.  1754.  Linnaeus  describes  4 
species,  B.  minor,  B.  media,  B.  maxima,  and  B.  eragrostis.  The  first  three  were 
familiar  to  Linnaeus  as  cultivated  plants  in  the  Hortus  Cliffortianus,  and  the 
second,  which  is  selected  as  the  type  species,  was  described  in  his  flora  of  Swe- 
den. The  first  three  species  are  now  retained  in  Briza,  the  last  is  referred  to 
Eragrostis. 

Of  the  three  species  found  in  this  country,  one,  Briza  media  (fig. 
14) ,  is  perennial,  and  two,  B.  minor  and  B.  maxima,  are  annual.  The 
spikelets  of  B.  maxima,  a  species  sometimes  cultivated  for  ornament 
under  the  name  quaking  grass,  are  large  and  showy,  half  an  inch  long, 
drooping  on  slender  pedicels.  Briza  minor,  with  smaller  upright 
spikelets,  is  rather  common  on  the  Pacific  coast. 

10.     ERAGROSTIS  Host. 

Spikelets  few  to  many  flowered,  the  florets  usually  closely  imbri- 
cate, the  rachilla  disarticulating  above  the  glumes  and  between  the 
florets,  or  continuous,  the  lemmas  deciduous,  the  paleas  persistent; 
glumes  somewhat  unequal,  shorter  than  the  first  lemma,  acute  or 
acuminate,  1-nerved,  or  the  second  rarely  3-nerved;  lemmas  acute 
or  acuminate,  keeled  or  rounded  on  the  back,  3-nerved,  the  nerves 
usually  prominent;  palea  2-nerved,  the  keels  sometimes  ciliate. 

Annual  or  perennial  grasses  of  various  habit,  the  inflorescence  an 
open  or  contracted  panicle.  Species  more  than  100,  tropical  and  tem- 
perate regions ;  33  species  in  the  United  States,  in  all  except  the  cool 
or  mountain  regions. 


46 


BULLETIN   772,   U.    S.   DEPARTMENT   OF   AGRICULTURE. 


Type  species :  Brisa  eragrostis  L. 

Eragrostis  Host,  Gram.  Austr.  4:  14,  pi.  24.     1809.     One  species  is  described, 
but  no  generic  description  is  given.     The  genus  Eragrostis  was  first  diagnosed 

by  Beauvois,1  the  type  being 
Eragrostis  eragrostis,  based  on 
Poa  eragrostis  L. 

Erochloe  Raf.,  Neogenyt.  4, 
1825;  Bull.  Bot.  Seringe  1:  221. 
1830.  Rafinesque  first  proposed 
the  name  in  1825  but  mentioned 
no  species.  In  1830  he  gives  the 
name  to  "  Poa  spectabilis  sen 
amabilis,"  (Eragrostis  pectina- 
cca  and  E.  amabilis,  respec- 
tively, not  the  same  species,  as 
Rafinesque  implies). 

Acamptoclados  Nash,  in  Small, 
Fl.  Southeast.  U.  S.  139.  1903. 
The  type,  indicated  on  page  1327, 
is  Eragrostis  sessilispica  Buckl., 
the  only  species  described.  The 
genus  is  placed  in  Chloridese  on 
account  of  the  sessile  spikelets 
distant  along  the  panicle 
branches. 

Neeragrostis  Bush,  Trans. 
Acad.  St.  Louis  13:  178.  1903. 
The  type  species  is  indicated, 
Poa  iccigeltiana  Reichenb.  The 
genus  includes  also  2V.  Jiypnoides 
( Eragros  Us  liypnoides ) . 

Erosion  Lunell,  Amer.  Midi. 
Nat.  4:  221.  1915.  Proposed  for 
"  Eragrostis  Beauv.  .  .  .  The 
name  to  be  avoided,  as  built  on 
another  grass  name." 


FIG.  14. — Quaking  grass,  Briza  media.     Plant,    X    \  ',  spikelet  and  floret,    X   5. 

In  many  species  the  rachilla  is  continuous  and  does  not  disarticulate 
as  in  most  species  of  the  tribe  Festuceae.  The  grain  is  free  and  falls 
with  the  lemma,  leaving  the  palea  upon  the  rachilla.  To  this  group 


1Ess.  Agrost.  70,  pi.  14,  f.  11.     1812. 


GENERA.   OF   GRASSES   OF   THE   UNITED  STATES.  47 

belong  two  common  annual  weeds,  Eragrostis  cilianensis  (All.)  Link 
(E.  mcgastachya  (Koel.)  Link,  E.  major  Host),  a  disagreeable  smell- 
ing grass  (fig.  15)  with  rather  compact  panicles  of  large  spikelets 
(3  mm.  wide),  the  keels  of  the  lemmas  glandular  dotted,  and  E.  caro- 
liniana  (Spreng.)  Scribn.,  with  open  panicles  of  small  spikelets 
(about  1.5  mm.  wide). 

Eragrostis  pectinacea  (Michx.)  Nees  (fig.  16)  is  a  perennial  with 
handsome  purple  open'panicles,  which  at  maturity  separate  from  the 
plant  and  tumble  before  the  wind. 

Eragrostis  Jiypnoides  (Lam.)  B.  S.  P.  is  a  spreading  dioecious 
annual  found  on  sandy  river  banks.  Eragrostis  ciliaris  (L.)  Link 
(fig.  17)  and  E.  amabilis  (L.)  Wight  and  Am.  (E.  plwmosa  Link) 
are  tropical  annuals  that  extend  into  the  Gulf  States.  They  have 
conspicuously  ciliate  paleas  and  disarticulating  rachilla.  A  common 
perennial  species  in  sandy  soil  from  Kansas  to  Texas  is  E.  secundiflora 
Presl  (E.  oxylepis  Torr.)  with  contracted  purple  panicles,  the  rachilla 
disarticulating  and  the  florets  falling  separately. 

In  general,  the  species  of  Eragrostis  have  little  forage  value. 

11.  CATABROSA  Beauv. 

Spikelets  mostly  2-flowered,  the  florets  somewhat  distant,  the 
rachilla  disarticulating  above  the  glumes  and  between  the  florets; 
glumes  unequal,  shorter  than  the  lower  floret,  flat,  nerveless,  irregu- 
larly toothed  at  the  broad  truncate  apex ;  lemmas  broad,  prominently 
3-nerved,  the  nerves  parallel,  the  broad  apex  scarious;  palea  about 
as  long  as  the  lemma,  broad,  scarious  at  the  apex. 

Aquatic  perennials,  with  creeping  bases,  flat  soft  blades,  and  open 
panicles.  Species  seven,  in  northern  Eurasia  and  North  America, 
extending  south  to  New  Brunswick  and  Colorado ;  one  in  Chile. 

Type  species :  Aira  aquatica  L. 

Gatabrosa  Beauv.,  Ess.  Agrost.  97,  pi.  19,  f.  8.  1812.  The  species  illustrated 
is  C.  aquaticd.  Another  name  mentioned  is  a  nomen  nudum. 

Catabrosa  aquatica  (L.)  Beauv.  (fig.  18)  is  found  in  mountain 
meadows  around  springs  and  watercourses.  It  is  an  unimportant 
forage  grass. 

12.  MOLINIA   Schrank. 

Spikelets  2  to  4  flowered,  the  florets  distant,  the  rachilla  disarticu- 
lating above  the  glumes,  slender,  prolonged  beyond  the  upper  floret, 
and  bearing  a  rudimentary  floret;  glumes  somewhat  unequal,  acute, 
shorter  than  the  first  lemma,  1-nerved ;  lemmas  membranaceous,  nar- 
rowed to  an  obtuse  point,  3-nerved;  palea  bowed  out  below,  equaling 
or  slightly  exceeding  the  lemma. 


48  BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 


FIG.   15. — Stink-grass,  Eragrostis  cittanensis.     Plant,    X    I ;   spikelet  and   floret,    X    5. 


GENERA  OF   GRASSES   OF  THE  UNITED   STATES. 


49 


FIG.  16. — Love-grass,  Eragrostis  pectinacea.     Plant   x    i  ;  spikelet  and  floret.   X   5. 
97769°— 19— Bull.  772 4 


Slender  tufted  perennials,  with  flat  blades  and  narrow,  rather  open 
panicles.  Species  five,  Europe  and  Asia;  one  sparingly  introduced 
in  the  United  States. 


FIG.  17. — Eragrostis  ciliaris.     Plant,   X   I  ;  spikelet  and  floret,    x  5. 

Type  species:  Aira  caerulea  L. 

Molinia  Schrank,  Baier.  Fl.  1:  33(5.  1789.  A  single  species  described,  J/. 
varia,  of  which  Aira  caerulea  L.  is  given  as  a  synonym. 

Molinia  caerulea  (L.)  Moench  (fig.  19)  is  introduced  in  a  few  local- 
ities in  the  Eastern  States  from  Xew  England  to  Pennsylvania.  In 
Europe  this  is  considered  to  be  a  good  forage  grass.  A  form  with 
striped  leaves  is  cultivated  for  ornament,  being  used  for  borders. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


51 


13.  DIAEINA  Raf. 

Spikelets    few-flowered,    the    rachilla    disarticulating    above    the 
glumes  and  between  the  florets;  glumes  unequal,  acute,  shorter  than 

the  lemmas,  the  first  1-nerved,  the 
second  3  to  5  nerved ;  lemmas  char- 
taceous,  pointed,  3-nerved,  the 
nerves  converging  in  the  point,  the 
upper  floret  reduced;  palea  char- 
taceous,  2-nerved,  obtuse,  at  ma- 
turity the  lemma  and  palea  widely 
spread  by  the  large  turgid  beaked 
caryopsis  with  hard  shining  peri- 
carp. 

Perennials,  with  slender  rhi- 
zomes, broadly  linear,  flat  blades, 
long-tapering  below,  and  narrow, 
few-flowered  panicles.  Species 
two,  one  in  eastern  Asia  and  one 
in  the  eastern  United  States. 

Type  species  :  Festuca  diandra  Michx. 
Diarina    Raf.,    Med.    R«pos.    5:   352. 
1808.    Rafinesque  bases  a  new  genus  on 


FIG.  18. — Catabrosa  aquatica.     Plant, 


Festuca  diandra  Michx.  (not  Moench,  1794).  He  renames  the  species  D.  festu- 
coides.  Beauvois a  spells  the.  name  Diarrhena,  crediting  it  to  "  S-hmal  "  [Rafin- 
esque-Schmalz]  and  renames  the  single  species  D.  americana. 


i  Ess.  Agrost.  142,  pi.  25,  f.  1.      1812. 


52 


BULLETIN   772,  U.   S.   DEPARTMENT  OF  AGRICULTURE. 


Korycarpus  Zea ;  Lag.,  Gen.  and  Sp.  Nov.  4.    1816.    The  only  species  described 
is  K.  arundinaceus  Zea,  which  is  the  same  as  Diarina  festucoides.    Lagasca  cites 

the  reference  "Ac.  Matr.  1806,"  but 
there  seems  to  be  no  evidence  that  the 
name  Korycarpus  was  published  earlier 
than  1816. 

Our  single  species,  Diarina 
f&stucoides  Raf.  (fig.  20),  is 
found  in  rich  woods  through 
the  eastern  United  States.  It  is 
of  little  importance  as  a  forage 
grass. 

14.    DlSSANTHE- 

LITJM  Trin. 

S  p  i  kelets 
mostly  2-flow- 
ered,  the  ra- 
chilla  slender, 
disarticulating 
the 


FIG.  19. — Molinia  caerulea.    Plant,   X   \  ',  spikelet  and  floret,  X  5. 

glumes  and  between  the  florets;  glumes  firm,  nearly  equal,  acumi- 
nate,  much   longer   than   the   lower   floret,   mostly    exceeding   all 


GENERA  OF  GRASSES  OP  THE  UNITED  STATES. 


53 


the  florets,  the  first  1-nerved,  the  second  3-nerved;  lemmas  strongly 
compressed,  oval  or  elliptic,  acute,  awnless,  3-nerved,  the  lateral 
nerves  near  the  margin ;  palea  some- 
what shorter  than  the  lemma. 

Annual  or  perennial  grasses,  with 
narrow  panicles.  Species  two,  one 
in  Mexico  and  South  America,  the 
other  in  California. 


PIG.  20. — Diarina  festucoides.     Plant,    X    \  ;  spikelet  and  floret,    X    5, 


54 


BULLETIN  772,  TJ.   S.   DEPARTMENT  OF  AGRICULTURE. 


Type  species:  Dissant  helium  supiuuni  Trin. 

Dissanthelium  Trin.,  Linnsea  10:  305.     1836.     One  species  described. 
Stenochloa  Nutt.,  Journ.  Acad.  Phita.  II.  1:  189.    1848.    One  species  described, 
&.  californica. 

Our    Calif  ornian    species,    Dissantheliwm    calif  omicum    (Nutt.) 
Benth.  (fig.  21),  is  an  annual  with  flat  blades  and  a  narrow  somewhat 

open  panicle.  It  is  a  rather 
rare  species  found  in 
southern  California  and 
the  islands  off  the  coast 
and  has  no  economic  value. 
The  second  species  of 
the  genus  is  Dissanthelium 
supinum  Trin.,  a  low 
tufted  perennial,  with  nar- 
row, folded  or  convolute 
blades  and  short,  densely 
flowered  panicles.  This  is 
found  on  alpine  summits 
in  Mexico,  Bolivia,  and 
Peru.  It  has  been  called 
Deschampsia  matthewsii 
Ball  and  Dissanthelium 
sclerochloides  Fourn. 

15.  REDFIELDIA  Vasey. 

Spikelets  compressed, 
few-flowered,  mostly  3  or 
4  flowered,  the  rachilla 
disarticulating  above  the 
glumes  and  between  the 
florets;  glumes  somewhat 
unequal,  1  -nerved,  acumi- 
nate; lemma  chartaceous, 
3-nerved,  the  nerves  paral- 
lel, densely  villous  at  base  ; 
pa  lea  as  long  as  the 
lemma;  grain  free. 

A  rather  tall  perennial, 
with  rhizomes  and  a  large 
panicle  with  diffuse  capil- 
lary branches.  Species 

One  5     Sand     hills     °f     the 
Great  Plains. 


FIG.  21. 


flfaaantoe.Hum  californium.     Plant,   X    ft 
spikelet  and  floret,  X  5. 


Type  species:  Graphephorum  flexuosum  Thurb. 
Redfieldia  Vasey,  Bull.  Torrey  Club  14:  133.     1887. 
R.  flexuosa  (Thurb.)  Vasey. 


One  species  described, 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


55 


FIG.  22. — Redfieldia  ftexuosa.    Plant,   X   I ;  spikelet  and  floret,   X  5. 

Redfieldia  flexuosa  (fig.  22)   is  a  gregarious  sand-hill  grass,  one 
of  the  few  species  found  growing  in  the  drifting  sand,  which  it  tends 


56  BULLETIN  772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

to  hold  in  place  with  its  numerous  creeping  rhizomes.  The  species 
is  found  from  South  Dakota  to  Kansas.  It  has  little  value  for 
forage  but  much  value  as  a  sand  binder. 

16.  MONANTHOCHLOE  Engelm. 

Plants  dioecious;  spike-lets  3  to  5  flowered,  the  uppermost  florets 
rudimentary,  the  rachilla  disarticulating  tardily  in  pistillate  spike- 
lets;  glumes  wanting;  lemmas  rounded  on  the  back,  convolute,  nar- 
rowed above,  several-nerved,  those  of  the  pistillate  spikelets  like 
the  blades  in  texture;  palea  narrow,  2-nerved,  in  the  pistillate  spike- 
lets  convolute  around  the  pistil,  the  rudimentary  uppermost  floret 
inclosed  between  the  keels  of  the  floret  next  below. 

A  creeping  wiry  perennial,  with  clustered  short  subulate  leaves,  the 
spikelets  at  the  ends  of  the  short  branches  only  a  little  exceeding  the 
leaves.  Species  two,  one  on  muddy  shores  of  the  ocean  in  tropical 
America,  one  in  Argentina. 

Type  species:  Monanthochloe  Httoralis  Engelm. 

Monanthochloe  Engelm.,  Trans.  Acad.  St.  Louis  1:  1436.  1859.  Only  one 
species  described. 

M onanthocJiloe  Httoralis  (fig.  23)  is  found  within  our  limits  only 
in  southern  Florida,  southern  Texas,  and  southern  California,  on 
tidal  flats,  sometimes  covering  extensive  areas.  Owing  to  the  incon- 
spicuousness  of  the  spikelets,  the  flowering  stage  can  be  determined 
only  on  close  examination.  The  species  has  no  economic  importance 
except  as  it  tends  to  convert  mud  flats  into  permanent  soil. 

The  leaves  next  the  spikelet  are  reduced,  but  always  present  a 
short  though  well-marked  blade  or  foliaceous  tip  with  a  distinct 
ligule.  The  branches  bearing  the  spikelets  are  short  and  clustered. 
The  uppermost  leaf,  the  one  nearest  the  spikelet,  usually  has  no  bud 
or  branch  in  its  axil.  The  leaf  next  below  bears  a  bud  or  short 
branch  and  a  well-developed  prophyllum.  The  prophylla  of 
branches  somewhat  lower  may  be 'as  large  as  the  sheath  of  the  leaf, 
and  the  two  nerves  may  extend  into  prominent  foliaceous  tips.  As 
the  branch  develops,  the  prophyllum  usually  splits  down  the  middle 
and  the  two  halves  stand  one  on  each  side.  The  uppermost  leaf 
sometimes  has  in  its  axil  a  thin  membranaceous  nerveless  obtuse 
bract  which  clasps  the  spikelets  like  a  second  (upper)  glume,  but 
probably  this  is  to  be  interpreted  as  a  prophyllum,  subtending  a 
branch  which  failed  to  develop. 

17.  DISTICHLIS  Raf. 

Plants  dioecious;  spikelets  several  to  many  flowered,  the  rachilla 
of  the  pistillate  spikelets  disarticulating  above  the  glumes  and 
between  the  florets;  glumes  unequal,  broad,  acute,  keeled,  mostly 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES. 


57 


3-nerved,  the  lateral  nerves  sometimes  faint  or  obscured  by  stria- 
tions  and  intermediate  nerves;  lemmas  closely  imbricate,  firm,  the 
pistillate  coriaceous,  the  margins  bowed  out  near  the  base,  acute  or 


acutish,  3-nerved,  with  several  intermediate  nerves  or  striations; 
palea  as  long  as  the  lemma  or  shorter,  the  pistillate  coriaceous,  in- 
closing the  grain. 


58  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

Low  perennials,  with  extensively  creeping  scaly  rhizomes,  erect, 
rather  rigid  stems,  and  short,  dense,  rather  few-flowered  panicles. 
Species  about  six,  in  salt  marshes  of  the  coast  and  interior  in  America, 
one  extending  to  Australia ;  three  species  in  the  United  States,  one 
widely  distributed  and  two  confined  to  Texas  and  northern  Mexico. 

Type  species :  Uniola  spicata  L. 

Distichlis  Raf.,  Journ.  de  Phys.  89:  104.  1819.  Distichlis  maritima  is  indi- 
cated as  the  type  by  Rafinesque,  who  Drives  Uniola  spicata  L.  as  a  synonym. 

Brizopyrum  Presl,  Rel.  Haenk.  1:  280.  1830.  Presl  describes  five  species,  of 
which  the  first  two  belong  to  Distichlis.  None  is  figured.  The  first  species, 
B.  boreale  (DistichUs.  spicata),  is  selected  as  the  type. 

The  common  species,  Distichlis  spicata  (L.)  Greene  (fig.  24),  is 
found  along  both  coasts  and  in  salt  or  alkali  spots  in  the  interior, 
and  extends  southward  to  South  America  and  to  Australia.  It  is  an 
erect,  gregarious  grass  usually  not  more  than  a  foot  high,  with  pale 
spikelets,  the  staminate  having  a  softer  texture  than  the  pistillate. 
The  common  name  is  salt  or  alkali  grass,  though  these  names  are  some- 
times applied  to  other  species.  In  general  it  has  little  value  for 
forage  but  in  the  interior  basins,  such  as  the  vicinity  of  Salt  Lake,  it 
is  utilized  for  grazing  when  better  grasses  are  not  available.  The 
large  amount  of  salt  or  alkali  may  cause  digestive  disturbances. 
This  species  is  variable,  and  two  forms  have  been  distinguished  as 
species,  D.  stricta  (Torr.)  Ryclb.  and  D.  dentata  Rydb.,  both  from 
the  Western  States. 

The  two  species  of  the  Southwest  are  not  well  known.  Distichlis 
texana  (Yasey)  Scribn.,  a  larger  grass  than  D.  spicata,  with  less 
compressed  spikelets  and  a  long,  narrow,  loose  panicle,  is  found  from 
Texas  to  Durango.  Distichlis  multinervosa  (Yasey)  Piper  is  an 
anomalous  species  from  western  Texas  known  only  from  the  type 
collection.  It  differs  in  having  a  villous  rachilla  and  7-nerved  mem- 
branaceous  lemmas,  rounded  on  the  back  and  villous  on  the  lower 
part,  and  in  the  2-lobed  palea. 

18.  UNIOLA  L. 

Spikelets  3  to  many  flowered,  the  lower  one  to  four  lemmas  empty, 
the  rachilla  disarticulating  above  the  glumes  and  between  the  florets ; 
glumes  compressed-keeled,  rigid,  usually  narrow,  nerved,  acute  or 
acuminate,  or  rarely  mucronate ;  lemmas  compressed,  sometimes  con- 
spicuously flattened,  chartaceous,  many-nerved,  the  nerves  some- 
times obscure,  acute  or  acuminate,  the  empty  ones  at  the  base  usually 
successively  smaller,  the  uppermost  usually  reduced;  palea  rigid, 
sometimes  bowed  out  in  the  winged  keels. 

Perennial,  rather  tall,  erect  grasses,  with  flat  or  sometimes  convo- 
lute blades  and  narrow  or  open  panicles  of  compressed,  sometimes 
very  broad  and  flat  spikelets.  Species  nine,  all  North  American, 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  59 

six  being  represented  in  the  United  States,  these  inhabiting  the 
Southeastern  States,  some  species  extending  as  far  north  as  Long 
Island  and  as  far  west  as  Kansas  and  Texas. 


FIG.  24. — Salt-grass,  Distichlis  spicata.     Staminate  plant  and  a  pistillate  panicle,   X 
pistillate  spikelet  and  floret,    X    5. 

Type  species:  Uniola  paniculata  L. 

Uniola  L.,  Sp.  PI.  71,  1753 ;  Gen.  PL,  ed.  5,  32.  1754.  Linnreus  describes  two 
species,  U.  paniculata  and  U.  spicata.  The  first  species  is  selected  as  the  type. 
The  second  is  now  referred  to  Distichlis. 


60  BULLETIN   772,   IT.   S.   DEPARTMENT   OF   AGRICULTURE. 

Trisiola  Raf.,  Fl.  Ludov.  144.  1817.  A  single  species,  T.  paniculata,  based 
on  Uniola  paniculata  L.,  is  included. 

Nevroctola  Raf.,  Neogenyt.  4.  1825.  "Type  Uniola  maritima  or  paniculata." 
Uniola  maritima  Michx.  is  U.  paniculata  L. 

Chasmanthium  Link,  Hort.  Berol.  1 :  159.  1829.  A  single  species,  C.  gracile, 
based  on  Uniola  gracilis  Michx.,  is  included.  This  is*  the  .same  as  L'.  hu-a  (L.) 
B.  S.  P. 

Uniola  paniculata,  seaside  oats,  common  on  the  coastal  sand  dunes 
from  Virginia  to  Texas,  is  a  stout,  pale  grass,  with  extensively  creep- 
ing rhizomes,  long-attenuate,  firm  blades,  and  large,  drooping,  heavy, 
rather  compact  panicles  of  large,  flat,  stramineous  spikelets.  It  is  an 
excellent  sand  binder.  Uniola  latifolici  Michx.  (PI.  VI;  fig.  25)  is 
a  woodland  grass  with  broad  flat  blades  and  handsome,  open,  droop- 
ing, rather  few-flowered  panicles  of  large,  very  flat  green  spikelets. 
The  species  is  worthy  of  use  in  landscape  gardening.  This  and  the 
remaining  species  of  Uniola  are  of  minor  importance  as  forage 
grasses,  as  they  are  not  sufficiently  abundant.  The  seeds  of  U.  pal- 
meri  Vasey  are  used  for  food  by  the  Cocopa  Indians. 

19.  ARUNDO  L. 

Spikelets  several-flowered,  the  florets  successively  smaller,  the 
summits  of  all  about  equal,  the  rachilla  glabrous,  disarticulating 
above  the  glumes  and  between  the  florets ;  glumes  somewhat  unequal, 
membranaceous,  3-nerved,  narrow,  tapering  into  a  slender  point, 
about  as  long  as  the  spikelet;  lemmas  thin,  3-nerved,  densely  long- 
pilose,  gradually  narrowed  at  the  summit,  the  nerves  ending  in 
slender  teeth,  the  middle  one  longer,  extending  into  a  straight  awn. 

Tall  perennial  reeds,  with  broad  linear  blades  and  large  plumelike 
terminal  panicles.  Species  about  six,  in  the  warmer  parts  of  the 
Old  World ;  one  introduced  in  America. 

Type  species:  Arundo  donax  L. 

Arundo  L.,  Sp.  PI.  81,  1753 ;  Gen.  PI.,  ed.  5,  35.  1754.  Linmeus  describes  six 
C)  represents  the  spikelets  of  Arundo  donax,  which  is  fully  described  on  page 
Genera  Plantarum  is  "  Scheuch.  3:  14,  3."  Scheuchzer's  figure  14  (A,  B,  and 
C)  represents  the  spikelets  of  Arundo  donax,  which  is  fully  described  on  page 
159  of  Scheuchzer's  work,  Agrostographia.  Hence,  Arundo  donax,  the  second 
species  described  by  Linnreus,  is  the  type  species  of  the  genus.  The  other 
original  species  are  now  referred  as  follows :  A.  bambos  to  Bambos,  A.  phrag- 
mites  to  Phragmites,  A.  epificjos  and  A.  calamoffrostis  to  Calamagrostis,  .1. 
arenaria  to  Ammophila. 

Armulo  donax,  the  giant  reed  (PI.  VII;  fig.  26),  is  cultivated  as  an 
ornamental  grass  for  lawn  groups  or  borders.  In  tropical  America 
it  is  frequently  used  for  hedges,  and  the  stems  are  utilized  for  a 
variety  of  purposes,  such  as  the  making  of  lattices  in  the  construction 
of  huts.  The  giant  reed  has  become  naturalized  in  the  Southwestern 
States  and  sometimes  forms  a  dense  growth  along  irrigation  ditches. 
There  is  a  cultivated  ornamental  variety  with  white-striped  blades 
(A.  donax  versicolor  (Mill.)  Kunth) .  This  was  mentioned  in  Miller's 
Gardener's  Dictionarv  in  1768  as  Arundo  versicolor. 


Bui.  772,  U.  S.  Dept.  of  Agriculture 


PLATE  VII, 


GIANT  REED  (ARUNDO  DONAX).    CULTIVATED  FOR  ORNAMENT. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  VIM, 


ORCHARD  GRASS  (DACTYLIS  GLOMERATA)  IN  FLOWER. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


61 


FIG.  25. — Uniola  latifolia.     Plant,   X    i  ;  spikelet  and  floret,   X   3. 


62  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  26. — Giant  reed,  Arundo  donax.     Rhizome,  leaves,  and  panicle,    X    J  ;  spikelet  and 

floret,    X    3. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  63 

The  giant  reed  is  one  of  the  largest  of  the  herbaceous  grasses,  its 
stem  being  as  much  as  20  feet  tall.  Ordinarily  it  grows  in  cultiva- 
tion to  a  height  of  6  to  10  feet.  The  rhizome  is  thick  and  knotty. 
The  blades  are  flat,  2  to  3  inches  broad  (smaller  on  the  branches), 
and  distributed  rather  equally  along  the  culm,  the  distichous  ar- 
rangement being  conspicuous.  The  handsome  feathery  panicle  is  1 
to  2  feet  long,  the  spikelets  being  about  one-half  inch  long.  In 
the  Southwest  this  is  sometimes  called  by  the  Mexican  name  carrizo. 
The  stems  of  the  giant  reed  are  used  for  making  clarionet  and  organ- 
pipe  reeds. 


Two  large  cultivated  grasses  or  reeds  allied  to  Arundo  are  Gyne- 
rium  and  Cortaderia. 

Gynerium  Humb.  and  Bonpl.,  PI.  Aequin.  2:  105,  pi.  115.  1809. 
The  single  species  described  and  figured  is  G.  saccharoides  Humb. 
and  Bonpl.  This  species,  now  called  G.  sagittatum  (Aubl.)  Beauv., 
is  a  giant  dioecious  grass  as  much  as  30  or  40  feet  tall,  with  culms 
clothed  below  with  old  sheaths  from  which  the  blades  have  fallen, 
sharply  serrulate  blades,  commonly  6  feet  long  and  about  2  inches 
wide  (forming  a  great  fan-shaped  summit  to  the  sterile  culms),  and 
pale,  plumy,  densely  flowered  panicles  3  or  more  feet  long,  the  main 
axis  erect,  the  branches  drooping;  spikelets  several-flowered,  the 
pistillate  with  long-attenuate  glumes  and  smaller  long-silky  lemmas, 
the  staminate  with  shorter  glumes  and  glabrous  lemmas.  This  grass, 
found  along  streams  in  tropical  America,  is  cultivated  occasionally 
in  greenhouses  under  the  name  of  uva  grass. 

Cortaderia  Stapf,  Gard.  Chron.  III.  22:  396.  1897.  Stapf  in- 
cludes five  species  in  the  genus,  the  first  of  which  is  C.  argentea. 
The  genus  is  technically  designated,  on  the  page  indicated  in  the 
citation,  but  on  a  preceding  page  (p.  378)  he  says,  "Taking  Gyne- 
rium argenteum  as  representative  of  the  Cortaderas,  .  .  .".  Hence 
Gynerium  argenteum  is  selected  as  the  type.  This  species,  called 
C.  argentea  (Nees)  Stapf,  is  an  erect  dioecious  perennial  reed,  grow- 
ing in  large  bunches,  with  numerous  long,  narrow,  basal  blades,  very 
rough  on  the  margins,  and  stout  flowering  culms  6  to  10  feet  high, 
with  beautiful  feathery,  silvery  white  or  pink  panicles  or  plumes  1  to 
3  feet  long;  spikelets  2  to  3  flowered,  the  pistillate  silky  with  long 
hairs,  the  staminate  naked;  glumes  white  and  papery,  long  and 
slender;  lemmas  bearing  a  long  slender  awn.  This  grass,  called 
pampas  grass,  is  a  native  of  Argentina.  It  is  cultivated  as  a  lawn 
ornamental,  being  hardy  in  the  warmer  parts  of  the  United  States. 
Pampas  grass  is  cultivated  commercially  in  southern  California  for 
the  plumes,  which  are  used  for  decorative  purposes.  The  plants 
grow  here  to  enormous  size,  as  much  as  20  feet  in  height. 


64  BULLETIN   772,    U.    S.   DEPARTMENT   OF   AGRICULTURE. 

20.  PHRAGMITES  Adans.,  the  reeds. 

Spikelets  several-flowered,  the  rachilla  clothed  with  long  silky  hairs, 
disarticulating  above  the  glumes  and  at  the  base  of  each  joint  between 
the  florets,  the  lowest  floret  staminate  or  neuter ;  glumes  3-nerved,  or 
the  upper  5-nerved,  lanceolate,  acute,  unequal,  the  first  about  half 
as  long  as  the  upper,  the  second  shorter  than  the  florets;  lemmas 
narrow,  long-acuminate,  glabrous,  3-nerved,  the  florets  successively 
smaller,  the  summits  of  all  about  equal ;  palea  much  shorter  than  the 
lemma. 

Perennial  reeds,  with  broad,  flat  linear  blades  and  large  terminal 
panicles.  Species  three,  one  in  Asia,  one  in  Argentina,  and  one  cos- 
mopolitan. 

Type  species:  Arundo  phragmites  L. 

Phragmites  Adans.,  Fam.  PI.  2:  34,  559.  1763.  Adanson  cites  "Arundo 
Scheuz.  161,"  which  Linnasus  also  cites  under  Arundo  phragmites.  Adanson 
cites  besides  four  other  pre-Linnsean  references,  two  of  them  queried.  The  other 
two,  which  may  refer  to  sugar  cane  or  to  sorghum,  are  to  be  excluded  because 
the  few  generic  characters  given,  especially  that  the  spikelets  have  several  per- 
fect flowers,  do  not  at  all  apply  to  them,  but  do  apply  to  Arundo  phragmites. 
Trinius *  publishes  Phragmites  as  a  new  genus  based  on  Arundo  phragmites  L., 
changing  the  specific  name  to  P.  communis. 

Trichoon  Roth,  Archiv  Bot.  Roemer  I3:  37.  1798.  Based  on  Arundo  karka 
Retz.,  an  East  Indian  species  of  Phragmites. 

Miphragtes  Nieuwl.,  Amer.  Midi.  Nat.  3:  332.  1914.  The  name  suggested  for 
Phragmites  Trin.  not  Phragmites  Adans.  in  case  Trichoon  Roth  and  Oxyanthe 
Steud.,  to  each  of  which  Nieuwland  transfers  the  specific  name  "  Phragmites," 
should  not  "be  applicable." 

Our  single  species  Phragmites  communis  Trin.  (P.  phragmites  (L.) 
Karst.)  (fig.  27)  is  a  tall  reed  with  creeping  rhizomes,  leaves  about 
an  inch  broad,  and  panicles  commonly  a  foot  long.  It  grows  in 
marshes,  around  springs,  and  along  lakes  and  streams  throughout  the 
United  States.  Besides  the  rhizomes  it  produces  extensively  creep- 
ing leafy  stolons.  In  the  Southwest  this  species,  in  common  with 
Arundo  donax,  is  called  by  the  Mexican  name  carrizo  and  is  used  for 
lattices  in  the  construction  of  adobe  huts.  The  stems  were  used  by 
the  Indians  for  the  shafts  of  arrows,  and  in  Mexico  and  Arizona  for 
mats  and  screens. 

21.  DACTYLIS  L. 

Spikelets  few-flowered,  compressed,  finally  disarticulating  between 
the  florets,  nearly  sessile  in  dense  one-sided  fascicles,  these  borne  at 
the  ends  of  the  few  branches  of  a  panicle ;  glumes  unequal,  carinate, 
acute,  hispid-ciliate  on  the  keel;  lemmas  compressed-keeled,  mucro- 
nate,  5-nerved,  ciliate  on  the  keel. 

Perennials,  with  flat  blades  and  fascicled  spikelets.  Species  two 
or  three,  in  Eurasia ;  one,  Dactylis  glomerata,  a  native  of  Europe,  cul- 
tivated and  naturalized  in  the  United  States. 

1  Fund.  Agrost.  134.     1820. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES. 


65 


FIG.  27. — Reed,  Phragmites  communis.     Rhizomes,  leaves,  and  panicles,    X    $  ',  spikelet 

and  floret,    X   3. 

97769°— 19— Bull.  772 5 


66  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  28. — Orchard  grass,  Dactylis  glomerata.     riant,   X   I  ;  spikelet  and  floret,   X   5. 


GENERA.  OF  GRASSES  OF  THE   UNITED  STATES. 


67 


Type  species:  Dactylis  ylomerata  L. 

Dactylis  L.,  Sp.  PI.  71,  1753 ;  Gen.  PL,  ed.  5,  32.  1754.  Linnaeus  describes  two 
species,  D.  cynosuroides  from  Virginia,  and  D.  glomerata  from  Europe.  The 
latter  species  being  described  in  his  flora 
of  Sweden  is  chosen  as  the  type. 

Dactylis  glomerata,  orchard  grass 
(PL  VIII;  fig.  28),  is  a  well-known 
meadow  and  pasture  grass,  cultivated 
in  the  humid  region  of  the  United 
States.  It  is  a  rather  coarse,  erect, 
perennial  bunch-grass,  soon  forming 
large  tussocks,  with  culms  2  to  1 
feet  tall,  flat  blades  as  much  as  one- 
third  of  an  inch  wide,  panicles  3  to  8 
inches  long,  with  a  few  stiff  branches, 
spreading  in  flower,  appressed  in 
fruit.  In  England  this  is  called 
cocksfoot  grass.  Orchard  grass  is 
recommended  for  shaded  situations, 
as  it  withstands  shade  better  than  our 
other  meadow  grasses. 

22.  CYNOSURUS  L. 

Spikelets  of  two  kinds,  sterile  and 
fertile  together,  the  fertile  sessile, 
nearly  covered  by  the  short-pediceled 
sterile  one,  these  pairs  imbricate  in  a 
dense  one-sided  spikelike  panicle; 
sterile  spikelets  consisting  of  two 
glumes  and  several  narrow,  acumi- 
nate, 1-nerved  lemmas  on  a  continu- 
ous rachilla;  fertile  spikelets  2  or  3 
flowered,  the  glumes  narrow,  the 
lemmas  broader,  rounded  on  the  back, 
awn-tipped,  the  rachilla  disarticulat- 
ing above  the  glumes. 

Species  four,  in  the  Mediterranean 
region ;  one  occasionally  cultivated  in 
the  United  States  and  sparingly  es- 
caped into  waste  places. 

Type  species :  Cynosurus  cristatus  L. 

Cynosurus  L.,  Sp.  PI.  72,  1753;  Gen.  PI., 
ed.  5,  33.  1754.  Linnaeus  describes  nine 
species.  The  first  species,  C.  cristatus,  is 
chosen  as  the  type  because  it  is  an  eco- 
nomic species  and  is  one  of  three  species 
described  in  his  flora  of  Sweden.  Of 
the  remaining  Linnsean  species,  one,  C.  echinatus,  is  now  retained  in  Cyno- 
surus;  (7.  lima  is  referred  to  Wangenheimia ;  C.  durus,  to  Scleropoa ;  C.  coeru- 
leus,  to  Sesleria;  C.  aegyptius,  to  Dactyloctenium ;  C.  indicus,  to  Eleusine;  O. 
paniceus,  to  Polypogon ;  C.  aureus,  to  Achyrodes. 


FIG.  29. — Crested  dog's-tail  grass, 
Cynosurus  cristatus.  Plant,  X  i  ; 
fertile  spikelet  and  floret,  X  5. 


68  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

The  only  species  in  the  United  States  is  Cynosurus  cristatus  L.  (fig. 
29),  known  as  crested  dog's-tail  grass.  This  is  occasionally  sown  in 
mixtures  for  meadows,  but  has  nothing  especially  to  recommend  it- 
It  is  a  tufted  perennial  1  to  2  feet  tall,  the  panicles  2  to  4  inches  long. 

23.  ACHYRODES  Boehmer. 
(Lamarckia  Moench.) 

Spikelets  of  two  kinds,  in  fascicles,  the  terminal  one  of  each  fas- 
cicle fertile,  the  others  sterile;  fertile  spikelet,  with  1  perfect 
floret,  the  rachilla  produced  beyond  the  floret,  bearing  a  small  awned 
empty  lemma  or  reduced  to  an  awn;  glumes  narrow,  acuminate  or 
short-awned,  1-nerved;  lemma  broader,  raised  on  a  slender  stipe, 
scarcely  nerved,  bearing  just  below  the  apex  a  delicate  straight  awn ; 
sterile  spikelets  linear,  1  to  3  in  each  fascicle,  consisting  of  2 
glumes  similar  to  those  of  the  fertile  spikelet,  and  numerous  distich- 
ously  imbricate,  obtuse,  awnless,  empty  lemmas. 

A  low,  erect  annual,  with  flat  blades  and  oblong,  one-sided,  compact 
panicles,  the  crowded  fascicles  drooping,  the  fertile  being  hidden,  ex- 
cept the  awns,  by  the  numerous  sterile  ones.  Species  one,  a  native  of 
southern  Europe,  naturalized  in  southern  California. 

Type  species:  Cynosurus  aureus  L. 

Achyrodes  Boehmer,  in  Ludw.  Def.  Gen.  PI.  420.  3760.  The  genus  is  based  on 
a  phrase  name  of  Tournefort,  which  Linnreus  cites  under  Cynosurus  aureus  L. 

Lamarckia  Moench,  Meth.  PI.  201.  1794.  A  single  species  is  described,  L. 
aurea  (Cynosurus  aureus  L.). 

Chrysurus  Pers.,  Syn.  PI.  1:  80.  1805.  A  single  species,  C.  cynosuroidcs, 
based  on  Cynosurus  aureus  L.,  is  included. 

The  single  species,  AcJiyrodes  aureum  (L.)  Kuntze  (fig.  30),  is 
abundantly  naturalized  in  southern  California.  It  is  called  golden- 
top  because  of  its  beautiful  golden  yellow  panicles. 

24.  MELICA  L. 

Spikelets  2  to  several  flowered,  the  rachilla  disarticulating  above 
the  glumes  and  between  the  florets,  prolonged  beyond  the  perfect 
florets  and  bearing  at  the  apex  two  or  three  gradually  smaller  empty 
lemmas,  convolute  together  or  the  upper  inclosed  in  the  lower; 
glumes  somewhat  unequal,  thin,  often  papery,  scarious-margined, 
obtuse  or  acute,  sometimes  nearly  as  long  as  the  lower  floret,  3  to  5 
nerved,  the  nerves  usually  prominent ;  lemmas  convex,  several-nerved, 
membranaceous  or  rather  firm,  scarious-margined,  sometimes  con- 
spicuously so,  awnless  or  sometimes  awned  from  between  the  teeth  of 
the  bifid  apex. 

Bather  tall  perennials,  with  the  base  of  the  culm  often  swollen 
into  a  corm,  with  closed  sheaths,  usually  flat  blades,  narrow  or  some- 
times open,  usually  simple  panicles  of  relatively  large  spikelets. 
Species  about  60,  in  the  cooler  parts  of  both  hemispheres;  18  in  the 
United  States,  mostly  woodland  grasses. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  69 

Type  species:  Melica  nutans  L. 

Melica  L.,  Sp.  PI.  66,  1753;  Gen.  PL,  ed.  5,  31.  1754.  Linnreus  describes  three 
species,  M.  ciliata,  M.  nutans,  and  M.  altissima,  all  species  of  Eurasia  and  all 
now  retained  in  the  genus  Melica.  In  the  Flora  Lapponica,  where  the  generic 
name  was  first  used,  the  only  species  described  is  referred  by  Linnaeus  in  the 
Species  Plantarum  to  M.  nutans;  hence  this  species  is  selected  as  the  type. 

Bromelica  Farwell,  Rhodora  21:  77.  1919.  Based  on  Melica,  section 
Bromelica  Thurb.,  of  which  the  type  is  M.  Itromoides  Gray  (M.  yeyeri  Munro). 

l 


FIG.  30. — Golden-top,  AcJiyrodes  aureum.     Plant,    X   \  ;  fertile  spikelet  and  floret,    X    5. 

In  our  eastern  species,  Melica  mutica  Walt.  (fig.  31)  and  M.  nitens 
Nutt.,  the  sterile  lemmas  form  a  rather  prominent  truncate  or  hood- 


70  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


FIG.  31. — Melica  mutica.     Plant,    X    I  ;  spikelet  and  floret,    X    5. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  71 

shaped  body  back  of  the  upper  floret,  and  the  glumes  and  fertile 
lemmas  are  conspicuously  scarious.  In  many  of  the  western  species 
the  sterile  lemmas  are  small  and  narrow,  forming  an  inconspicuous 
body  at  the  top  of  the  rachilla,  and  the  glumes  and  fertile  lemmas  are 
either  broad  or  rather  narrow  with  less  conspicuous  scarious  margins. 
In  J/.  imperfecta  Trin.,  of  California,  there  is  but  one  fertile  floret. 
One  group  of  species  with  narrow,  scarcely  flattened  spikelets  and 
little-differentiated  upper  florets  has  been  segregated  as  a  section 
under  the  name  Bromelica.  The  awned  species  of  the  genus,  M.  aris- 
tata  Thurb.  (fig.  32),  M.  smithii  (Porter)  Vasey,  and  M.  purpu- 
rascens  (Torr.)  Hitchc.,  belong  to  this  group.  The  inflorescence  of 
Melica  is  usually  narrow,  a  simple  panicle  or  even  a  raceme,  but  in 
M.  smithii,  M.  geyeri  Munro,  and  M.  nitens  it  may  be  an  open  but 
rather  few-flowered  panicle.  The  corms  produced  by  many  species 
are  characteristic  and  have  suggested  the  name  onion  grass  often 
applied  to  them.  The  genus  is  distinguished  from  allied  genera  by 
the  scarious  margins  of  the  glumes  and  lemmas.  The  awned  species 
of  the  section  Bromelica  approach  closely  to  Bromus. 

The  species  of  Melica,  commonly  called  melic  grasses,  are  in  gen- 
eral excellent  forage  grasses.  They  are,  however,  not  gregarious, 
and  do  not  ordinarily  furnish  any  large  proportion  of  the  forage  of 
the  ranges.  The  two  most  important  species  on  the  ranges  are  M. 
lella  Piper  and  M.  spectabilis  Scribn.  They  have  broad  spikelets, 
bulbous  bases,  and  narrow  panicles,  the  first  with  erect  pedicels,  the 
second  with  slender  recurved  pedicels. 

25.  ANTHOCHLOA  Nees. 

Spikelets  few-flowered,  subsessile,  on  a  simple  axis  and  imbricate, 
the  rachilla  disarticulating  above  the  glumes  and  between  the  florets ; 
glumes  (in  our  species)  wanting;  lemmas  thin-membranaceous,  flabel- 
liform,  whitish,  petallike,  many  nerved;  palea  narrower  than  the 
lemma,  hyaline. 

Low  annuals  or  perennials,  with  close,  spikes.  Species  three ;  two 
in  the  Andes,  one  in  California. 

Type  species :  Anthochloa  lepidiila  Nees. 

Anthochloa  Nees;  Meyen,  Reise  urn  Erde  2:  14.  1835.  One  species  men- 
tioned. The  description  is  meager  and  scarcely  constitutes  technical  publica- 
tion. It  is  as  follows :  "  Wir  sammelten  hier  ein  sehr  kleines  aber  ausserst 
schones  Gras,  das  die  neue  Gattung  Anthochloa  bildet  und  von  Herrn  Nees  v. 
Esenbeck  Anthochloa  lepickula  genannt  worden  ist  (Anthochloa  genus  proximum 
Melicae,  differt  glumis  brevioribus,  valvula  superior!  quadrifida  ! ) ."  The  genus 
is  first  described  by  Endlicher1  but  no  species  is  mentioned.  Remy2  describes 
the  genus  and  one  species  (A.  rupestris). 

Stapfia  Davy,  Erythea  6:  110,  pi.  3,  1898,  not  Stapfia  Chodat,  1897.  One 
species  described,  S.  colusa-na. 

Neostapfia  Davy,  Erythea  7 :  43.     1899.     A  new  name  for  Stapfia  Davy. 

Davyella  Hack.,  Oesterr.  Bot.  Zeitschr.  49 :  133.  1899.  A  new  name  proposed 
for  Stapfia  Davy,  not  Chodat. 

1Gen.  PI.  99.     1836.  a  Ann.   Sci.  Nat.   Bot.   III.   6:347.     1846. 


72  BULLETIN  772,   IT.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  32. — Melica  aristata.     Plant,    X    I  ;  spikelet  and  floret,    X    5, 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  73 

Our  species,  Anthochloa  colwatw  (Davy)  Scribn.  (fig.  33),  is 
known  only  from  the  type  collection,  from  Colusa  County,  Calif.  It 
is  an  annual,  with  broad  flat  leaves  with  no  distinction  between 
sheath  and  blade,  and  dense  cylindric  spikes,  the  upper  part  of  the 
axis  bearing,  instead  of  spikelets,  lanceolate-linear  empty  bracts. 


FIG.  33. — Anthochloa  colusana.     Plant   X    £  ;  spikelet  and  floret,    X   5. 
26.  TRIODIA  R.  Br. 

Spikelets  several-flowered,  the  rachilla  disarticulating  above  the 
glumes  and  between  the  florets;  glumes  membranaceous,  often  thin, 
nearly  equal  in  length,  the  first  sometimes  narrower,  1 -nerved  or  the 
second  rarely  3  to  5  nerved,  acute  or  acuminate;  lemmas  broad, 
rounded  on  the  back,  the  apex  from  minutely  emarginate  or  toothed 
to  deeply  and  obtusely  lobed,  3-nerved;  the  lateral  nerves  near  the 
margins,  the  midnerve  excurrent  between  the  lobes  as  a  minute  point 
or  as  a  short  awn,  the  lateral  nerves  often  excurrent  as  minute  points, 
all  the  nerves  pubescent  below  (subglabrous  in  one  species),  the  lat- 
eral ones  sometimes  conspicuously  so  throughout;  palea  broad,  the 
two  nerves  near  the  margin,  sometimes  villous. 

Erect,  tufted  perennials,  rarely  rhizomatous  or  stoloniferous,  the 
blades  usually  flat,  the  inflorescence  an  open  or  contracted  panicle, 
or  a  cluster  of  few-flowered  spikes  interspersed  with  leaves.  Species 
about  25,  mostly  in  America ;  15  species  in  the  United  States. 


74  BULLETIN   772,    U.    S.   DEPARTMENT   OF   AGRICULTURE. 

Type  species:  Triodia  pungcns  R.  Br. 

Trioclia  R.  Br.,  Prodr.  Fl.  Nov.  Holl.  1 :  182.  1810.  Six  species  are  described, 
tlie  first  of  which  is  selected  as  the  type.  In  this  the  lemma  is  firm,  rather  ob- 
scurely 3-nerved,  villous  along  the  lower  half  of  the  back  and  margins,  2-toothed 
at  the  summit,  the  midnerve  excurrent  between  the  acute  teeth  as  a  short  awn 
as  long  as  the  teeth,  the  lateral  nerves  extending  into  the  teeth. 

Tricuspis  Beauv.,  Ess.  Agrost.  77,  pi.  15,  f.  10,  1812,  not  Tricuspis  Pers.,  1807. 
The  figured  species  is  T.  caroliniana,  discussed  in  the  following  paragraph. 

Tridens  Roern.  and  Schult.,  Syst.  Yeg.  2 :  34.  1817.  Under  the  description  of 
the  genus  is  a  reference  to  a  figure  of  Beauvois.1  Beauvois  describes  the  figure 
(which  represents  Triodia  flava)  under  the  name  Tricuspis  caroliniana.  Under 
the  description  of  the  genus  (p.  77)  Beauvois  mentions  two  species,  Poa  caerules- 
fcns  Michx.  and  Tricuspis  novaeboracensis  Beauv.  Both  are  nomina  nuda,  the 
first  never  having  been  published  by  Michaux,  and  Beauvois  giving  no  descrip- 
tion of  the  second.  Roemer  and  Schultes  on  a  later  page  (p.  599)  describe  the 
single  species  referred  to  Tridens,  under  the  name  T.  quinquefida,  based  upon 
Poa  quinquefida  Pursh,  which  is  Triodia  flava. 

Windsoria  Nutt,  Gen.  PI.  1 :  70.  1818.  Two  species  are  described,  W.  poae- 
formis  Nutt.,  which  is  Triodia  flava,  and  TV7.  ambigita  (Ell.)  Nutt.  The  first  is 
selected  as  the  type. 

Rhombolytrum  Link,  Hort.  Berol.  2 :  296.  1833.  The  single  species  described 
is  R.  rhomboidea  from  Chile.  Bentham  and  Hooker  2  state  that  two  North  Ameri- 
can species,  Triodia,  albcscens  and  T.  trin-errif/1  urn-is,  are  allied  to  this.  Nash3 
recognizes  the  genus  Rhombolytrnni  and  transfers  to  it  Sieglingia  albescens 
(Vasey)  Kuntze. 

Erioneuron  Nash,  in  Small,  Fl.  Southeast.  U.  S.  143.  1903.  The  type,  Uralepis 
pilosa,  is  indicated  on  page  1327  of  the  same  work.  Only  one  species  included. 

Dasyochloa  Willd. ;  Rydb.,  Colo.  Agr.  Exp.  Sta.  Bull.  100:  37.  1906.  (Flora 
of  Colorado.)  The  name  first  appeared  in  Steudel's  Nomenclator  *  as  a  synonym 
of  Uralepis  (Uralepsis),  where  two  species  are  listed,  D.  avenacea  Willd.  and  D. 
pulchella  Willd.,  both  being  herbarium  names.  The  type  and  only  species  men- 
tioned is  D.  pulchella  (H.  B.  K.)  Willd. 

Some  authors  have  referred  our  species  to  Sieglingia  Bernh.5  The  type  of 
Sieglingia  is  Festuca  decumbens  L.  This  species  seems  to  represent  a  distinct 
genus,  differing  in  having  5  to  several  nerved  lemmas.  The  single  species,  /S. 
decumbens  (L.)  Bernh.,  a  native  of  Europe,  is  found  in  Newfoundland,  but  does 
not  occur  in  the  United  States. 

The  species  of  Triodia  are  diverse  in  habit  and  in  floral  characters, 
but  it  does  not  seem  practicable  to  segregate  any  of  them  as  distinct 
genera.  Triodia  flava  (the  type  of  Tridens)  and  T.  pulchella  (the 
type  of  Dasyochloa)  represent  the  two  extremes,  but  they  are  con- 
nected by  a  series  of  intergrading  species.  The  type  species  of 
Triodia,  T.  pungens,  of  Australia,  in  the  form  of  its  spikelets,  stands 
about  midway  between  our  two  extremes.  Its  spikelets,  though  less 
pubescent,  are  much  like  those  of  T.  avenacea,  with  the  midnerve  of 
the  lemma  excurrent  between  the  teeth,  the  lateral  nerves  not  ex- 
current  but  extending  into  the  teeth.  Triodia  putchella  H.  B.  K. 
(fig.  34)  differs  in  habit  from  all  the  other  species.  It  sends 
up  from  the  basal  cluster  of  leaves  slender  branches  with 
elongate  internodes,  which  produce  at  the  extremity  a  cluster 
of  short  leaves  and  short,  few-flowered  spikes.  Later  from  these 
clusters  are  produced  slender  branches,  which  in  their  turn  form 
clusters  of  leaves  and  spikelets.  The  clusters  bend  to  the  ground  and 
take  root,  so  that  ultimately  there  is  formed  a  colony  of  these  clusters 

1  Beauv.  Ess.  Agrost.  pi.  15,  f.  10.     1812.  *  Norn.  Bot,  ed.  2,  1:  484.     1840. 

2  Gen.  PI.  3:  1176.     1883.  -  6  Syst.  Verz.  Pflanz.   Erfurt.   40.      1800. 

3  In  Britton,  Man.  129.     1901. 


GENERA  OF  GRASSES   OF  THE   UNITED  STATES. 


75 


of  leaves  and  spikelets  connected  by  the  slender  internodes.     This 
species  and  two  others,  T.  avenacea  H.  B.  K.  and  T.  nealleyi  Vasey, 


-* 


agree  in  having  deeply  2-lobed  lemmas,  the  midnerve  excurrent  be- 
tween the  lobes  as  an  awn.  The  last  two  species  and  T.  pilosa  ( Buckl. ) 
Merr.  have  short,  spikelike  panicles,  but  the  last  species  differs  in 


76  BULLETIN   772,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 

having  acuminate  lemmas.  These  four  species  and  T.  mwtica  (Torr.) 
Scribn.  agree  in  having  woolly  lemmas,  the  lower  part  of  the  three 
nerves  being  long-villous,  and  in  having  paleas  villous  on  the  wings. 
Tmodia  rrmtica  has  a  somewhat  elongate  panicle  and  differs  in  having 
very  obtuse,  broad,  sometimes  minutely  notched,  awnless  lemmas,  the 
lateral  nerves  disappearing  before  reaching  the  margin.  The  afore- 
mentioned species  might  be  set  off  under  Erioneuron,  but  they  would 
not  form  a  coherent  group. 

Triodia  flava  (L.)  Hitchc.  (Poa  flava  L.)  (fig.  35)  has  an  open, 
elegantly  drooping  panicle  of  purple  spikelets,  the  nerves  of  the 
lemmas  pubescent  below,  extending  into  3  mucros.  This  is  common 
in  autumn  through  the  Eastern  States  in  meadows  and  open  wood- 
land and  is  sometimes  called  purple-top.  It  exudes  a  sticky  sub- 
stance on  the  culm  below  the  panicle  and  on  the  main  branches  of 
the  inflorescence,  to  which  dirt  adheres.  One  species,  T.  drum- 
mondii  Scribn.  and  Kearney,  produces  rhizomes. 

Three  species  (besides  T.  mutica  mentioned  above)  have  a  spike- 
like  panicle.  These  are  T.  aTbescens  Vasey,  with  glabrous  lemmas; 
T.  elongata  (Buckl.)  Scribn.,  with  glumes  nearly  as  long  as  the 
spikelet;  and  T.  stricta  (Nutt.)  Yasey,  with  shorter  glumes  but  mu- 
cronate  lemmas.  The  other  species  have  more  or  less  open  panicles. 

In  general  the  species  of  Triodia  are  of  little  importance  agricul- 
turally. Triodia  pulchella  is  often  abundant  on  the  ranges,  but  is 
not  relished  by  stock,  the  little  dry  plants  being  seldom  eaten. 

27.  TRIPLASIS  Beauv. 

Spikelets  few-flowered,  the  florets  remote,  the  rachilla  slender, 
terete,  disarticulating  above  the  glumes  and  between  the  florets; 
glumes  nearly  equal,  smooth,  1-nerved,  acute;  lemmas  narrow, 
3-nerved,  2-lobed,  the  nerves  parallel,  pubescent  or  villous,  the  lateral 
pair  near  the  margin,  the  midnerve  excurrent  as  an  awn,  as  long  as 
or  longer  than  the  lobes ;  palea  shorter  than  the  lemma,  2-keeled,  the 
keels  densely  long-ciliate  on  the  upper  half. 

Slender  tufted  annuals  or  perennials,  with  short  blades,  short,  open, 
few-flowered  purple  panicles  terminating  the  culms,  and  cleistoga- 
mous  narrow  panicles  in  the  axils  of  the  leaves.  Species  three ;  south- 
eastern United  States. 

Type  species :  Triplasis  americana  Beauv. 

Triplasis  Beauv.,  Ess.  Agrost.  81,  pi.  16,  f.  10.  1812.  The  single  species, 
T.  americana,  is  figured. 

Uralepis  Nutt.,  Gen.  PL  62.  1818.  Nuttall  describes  two  species,  U.  purpurea, 
based  on  Aira  purpurea  Walt.  (Triplasis  purjmrea  (Walt.)  Chapm.)  and  U. 
aristulata,  which  is  the  same  species.  The  first  is  selected  as  the  type.  The 
name  is  spelled  Uralepsis,  but  this  is  a  typographical  error.  Nuttall  states 
that  it  is  based  on  the  Greek  words  oiira  and  lepis. 

Diplocea  Raf.,  Amer.  Journ.  Sci.  1 :  252.  1819.  One  species  described,  D.  6or- 
bata,  which  is  the  same  as  Triplasis  purpurea. 

Merisachue  Steud.,  Syn.  PI.  Glum.  1:  117.  1854.  Contains  one  species, 
M.  drummondii  Steud.,  Drummond  330,  from  Texas  (Triplasis  purpurea). 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  77 


FIG.  35. — Purple-top,  Trwdia  fla>va.     Plant,   X    i  ;  spikelet  and  floret,   X   5. 


78  BULLETIN   772,  JJ.   S.   DEPARTMENT  OF  AGRICULTURE. 

The  three  species  are  found  in  sandy  soil  in  the  Eastern  States, 
Triplasis  purpivrea  (fig.  36)  from  Maine  to  Florida  and  from  the 
Great  Lakes  to  Texas.  Triplasis  intermedia  is  confined  to  Florida ; 
T.  americana  is  found  from  North  Carolina  to  Florida.  All  the  spe- 
cies, besides  the  small  panicles  of  cleistogamous  spikelets  in  the  upper 
sheaths,  have  additional  cleistogamous  spikelets,  reduced  to  a  single 
large  floret,  at  the  bases  of  the  lower  sheaths.  The  culms  break  at 
the  nodes  bearing  these  cleistogenes,  the  ripe  seed  remaining  attached 
to  the  internode.  The  species  are  of  no  importance  except  as  they 
tend  to  hold  sandy  soil. 

For  a  revision  of  the  species  of  Triplasis,  see  Nash,  Bull.  Torrey 
Club  25:561-565.  1898. 

28.  BLEPHAKIDACHNE  Hack. 

Spikelets  4-flowered,  the  rachilla  disarticulating  above  the  glumes 
but  not  between  the  florets;  glumes  nearly  equal,  about  as  long  as 
the  spikelet,  compressed,  1-nerved,  thin,  acuminate,  smooth;  lemmas 
deeply  3-lobed,  3-nerved,  the  first  and  second  sterile,  containing  a 
palea  but  no  flower,  the  third  fertile,  the  fourth  reduced  to  a  3-awned 
rudiment. 

Low  annuals  or  perennials,  with  short,  congested,  few-flowered 
panicles  scarcely  exserted  from  the  subtending  leaves.  Species  two ; 
one  in  Argentina,  one  in  Nevada. 

Type  species:  Eremochloe  kingii  S.  Wats. 

Eremochloe  S.  Wats.,  in  King,  Geol.  Expl.  40th  Par.  382,  pi.  40,  1871,  not 
Eremochloa  Biise,  1854.  Two  species  are  described,  one  E.  kingii  from  Nevada 
and  the  other,  in  a  footnote,  E.  bigelovii,  from  southern  New  Mexico.  The  two 
specimens  are  to  be  referred  to  the  same  species. 

Blepharidachne  Hack.,  in  Engl.  and  Prantl,  Pflanzenf am.  22 :  126.  1887.  In  a 
footnote  the  name  Blepharidachne  is  substituted  for  Eremochloe  S.  Wats., 
because  of  the  earlier  Eremochloa  Biise.  The  author  of  Blepharidachne  is  given 
as  "  Hook.,"  a  typographical  error  for  Hack. 

Blepharidachne  Jcingii  (S.  Wats.)  Hack.  (fig.  37),  found  on  the 
plains  and  foothills  of  Nevada  (and  New  Mexico  according  to 
Watson),  has  been  collected  only  a  few  times. 

A  second  species,  Blepharidachne  benthamiana  (Hack.)  Hitchc. 
(Munroa  benthamiana  Hack.1)  grows  in  dry  regions  of  Argentina. 
In  habit  it  resembles  our  Munroa  squarrosa,  but  in  floral  structure  it 
agrees  with  Blepharidachne,  having  two  sterile  florets,  one  fertile 
floret,  and  a  3-awned  rudiment. 

29.  OECTJTTIA  Vasey. 

Spikelets  several-flowered,  the  upper  florets  reduced;  rachilla  per- 
sistent, continuous,  the  florets  falling  away  or  tardily  disarticulating ; 
glumes  nearly  equal,  shorter  than  the  lemmas,  broad,  irregularly  2  to  5 

1  In  Kuntze,  Rev.  Gen.  PI.  32:  357.     1898. 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES. 


79 


r< 


FIG.  36. — Triplasis  purpurea.  Plant,  X  J  ;  spikelet,  floret  (above)  showing  beard  on  tbx 
nerves  of  the  palea  and  cleistogene  (at  left),  a  cleistogamous  fertile  1-flowered  spikelet 
from  the  axil  of  a  lower  leaf,  aJl  X  5. 


80 


BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 


toothed,  many-nerved,  the  nerves  extending  into  the  teeth;  lemmas 
firm,  prominently  13  to  15  nerved,  the  broad  summit  with  5  long 


FIG.   37.  —  Blepharidachne  kingii.     Plant,    X    1  ;   spikelet   and  perfect  floret,   the  latter 
showing  the  rudiment  behind  the  palea,   X   5. 

teeth  or  with  numerous  short  teeth  ;  palea  broad,  2-nerved,  as  long  as 

the  lemma. 

Low  cespitose  annuals,  with  short  blades  and  terminal  spikelike 

racemes,  the  spikelets  rel- 
atively large,  appressed, 
the  upper  aggregate,  the 
lower  more  or  less  remote. 
Species  two  ;  California 
and  Lower  California. 

Type  species:  Orcuttia  call- 
f  arnica  Vasey. 

Orcuttia  Vasey,  Bull.  Tor- 
rey  Club  13  :  219,  pi.  16.  1886. 
The  one  species  described  was 
collected  by  C.  R.  Orcutt  at 
San  Quentin  Bay,  Lower  Cali- 
fornia. 

Our  species,  both  in 
California,  are  Orcuttia 
greenei  Vasey,  from  Chico, 
of  which  only  the  type 
collection  is  known,  and 
0.  calif  omica  (fig.  38), 
has  been  collected 


no.  8a-ora,«io  cau/orntca.    Plant,  x  i;  .pikelet 

and    floret,    the    latter    without    a    joint    of    the  at  GrOOSe   Valley,      llielat- 
rachilla,   this  not  disarticulating,    X    5.  ter  Species  is  distinguished 

by  having  5-toothed  lemmas;  0.  greenei  has  truncate  lemmas,  the 
nerves  extending  into  short  points. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  81 

30.  SCLEROPOGON  Philippi. 

Plants  dioecious.  Staminate  spikelets  several-flowered,  pale,  the 
rachilla  not  disarticulating;  glumes  about  equal,  a  perceptible  inter- 
node  between,  membranaceous,  long-acuminate,  1-nerved  or  obscurely 
3-nerved,  nearly  as  long  as  the  first  lemma;  lemmas  similar  to  the 
glumes,  somewhat  distant  on  the  rachilla,  3-nerved  or  obscurely  5- 
nerved,  the  apex  mucronate;  palea  obtuse,  shorter  than  the  lemma. 
Pistillate  spikelets  several -flowered,  the  upper  florets  reduced  to 
awns,  the  rachilla  disarticulating  above  the  glumes  but  not  separat- 
ing between  the  florets  or  only  tardily  so;  glumes  acuminate,  3- 
nerved,  with  a  few  fine  additional  nerves,  the  first  about  half  as  long 
as  the  second ;  lemmas  narrow,  3-nerved,  the  nerves  extending  into  3 
slender,  scabrous,  spreading  awns,  the  florets  falling  together  forming 
a  cylindric  many-awned  fruit,  the  lowest  floret  with  a  sharp-bearded 
callus  as  in  Aristida ;  palea  narrow,  the  two  nerves  near  the  margin, 
produced  into  short  awns. 

A  perennial  stoloniferous  grass,  with  short  flexuous  blades  and 
narrow  few-flowered  racemes  or  simple  panicles,  the  staminate  and 
pistillate  strikingly  different  in  appearance.  Species  one;  Chile  to 
southwestern  United  States. 

Type  species:  Scleropogon  brevifolius  Philippi. 

Scleropogon  Philippi,  Anal.  Univ.  Chile  36:  205.  1870.  Only  one  species  de- 
scribed. 

Lesourdia  Fourn.,  Bull.  Soc.  Bot.  France  2  7 :  102,  pi.  3,  4.  1880.  Two  species 
Are  proposed,  L.  multlflora  and  L.  kar wins ky ana,  both  referable  to  the  same 
species,  Scleropogon  brevifolius. 

This  species  (fig.  39)  is  found  on  semiarid  plains  and  open  valley 
lands  from  southern  Colorado  to  Texas  and  Arizona  and  southward. 
The  mature  pistillate  spikelets  break  away  and  with  their  numer- 
ous long  spreading  awns  form  "  tumbleweeds  "  that  are  blown  before 
the  wind.  The  pointed  barbed  callus  readily  penetrates  clothing  or 
wool,  the  combined  florets  acting  like  the  single  floret  of  the  long- 
awned  aristidas.  As  a  forage  grass,  this  is  inferior  to  grama ;  but  on 
overstocked  ranges,  where  it  tends  to  become  established,  it  is  use- 
ful in  preventing  erosion.  It  is  called  burro  grass. 

31.  COTTEA  Kunth. 

Spikelets  several-flowered,  the  uppermost  reduced,  the  rachilla  dis- 
articulating above  the  glumes  and  between  the  florets;  glumes  two, 
about  equal,  nearly  equaling  the  lower  lemma,  with  several  parallel 
nerves ;  lemmas  rounded  on  the  back,  villous  below,  prominently  9  to  11 
nerved,  the  nerves  extending  partly  into  awns  of  irregular  size  and 
partly  into  awned  teeth ;  palea  awnless,  a  little  longer  than  the  body 
of  the  lemma. 

97769°— 19— Bull.  772 6 


82  BULLETIN   772,   TJ.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  39. — Burro  grass,  Scleropogon  brevifolius.     Pistillate    (left)    and  staminate  plants, 
X   i  ;  pistillate  spikelet,    X   2  ;  pistillate  and  staminate  floret,    X    5. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  83 

An  erect  tufted  branching  perennial,  with  oblong  open  panicles. 
Species  one;  western  Texas  to  southern  Arizona  and  southward  to 
Argentina. 

Type4  species:  Cottcu  pappophoroides  Kunth. 

Cottea  Kunth,  Rev.  Gram.  1:  84.  1829.  A  single  species  mentioned,  from 
Peru. 

This  genus  is  allied  to  Pappophorum  and  very  closely  related  to 
Anthoschmidtia  of  Africa.  It  differs  from  the  first  in  the  several- 
flowered  spikelets  that  separate  between  the  florets  and  in  the  awns 
interspersed  with  awned  teeth.  Anthoschmidtia  differs  in  having 
glumes  longer  than  the  florets  and  in  having  lemmas  with  five  awns 
alternating  with  four  lobes. 

Cottea  pappophoroides  Kunth  (fig.  40)  is  not  abundant  enough  to 
have  agricultural  importance  in  the  United  States.  Cleistogenes  are 
produced  in  the  lower  sheaths.1 

32.  PAPPOPHORUM   Schreb. 

Spikelets  2  to  5  flowered,  the  upper  reduced,  the  rachilla  disarticu- 
lating above  the  glumes  but  not  between  the  florets,  the  internodes 
very  short;  glumes  nearly  equal,  keeled,  thin-membranaceous,  as  long 
as  or  longer  than  the  body  of  the  florets,  1  to  several  nerved,  acute; 
lemmas  rounded  on  the  back,  firm,  obscurely  many  nerved,  dissected 
above  into  numerous  spreading  scabrous  or  plumose  awns,  the  florets 
falling  together,  the  awns  of  all  forming  a  pappuslike  crown ;  palea 
as  long  as  the  body  of  the  lemma,  2-nerved,  the  nerves  near  the 
margin. 

Erect,  cespitose  perennials,  with  narrow  or  spikelike  tawny  or 
purplish  panicles.  Species  20,  in  the  dry  parts  of  the  Old  World,  in 
Australia,  and  from  Texas  to  Argentina;  3  species  in  the  United 
States,  from  Texas  to  Arizona. 

Type  species:  Pappophorum  alopecuroideum  Vahl. 

Pappophorum  Schreb. ;  Vahl,  Symb.  Bot.  3 :  10.  1794.  Only  one  species  de- 
scribed. 

Enneapogon  Desv. ;  Beauv.,  Ess.  Agrost.  81,  pi.  16,  f.  11.  1812.  Beauvois  men- 
tions Enneapogon  desvauxii,  Pappophorum  gracile,  P.  nigricans,  P.  pallidum, 
and  P.  purpurascens.  The  first  one,  being  figured,  is  selected  as  the  type. 

Polyrhaphis  (Trin.)  Lindl.,  Veg.  Kingd.  115.  1847.  Based  on  Pappophorum, 
section  Polyrhaphis  Trin.,  under  which  a  single  species,  P.  alopecuroides  Vahl, 
is  included. 

Pappophorum  bicolor  Fourn.,  with  purplish,  rather  loose  panicles, 
is  found  in  southern  and  western  Texas ;  P.  vaginatum  Buckl.  (fig.  41) , 
with  pale,  slender,  spikelike  panicles,  and  P.  wrightii  S.  Wats.  (fig. 
42),  with  plumbeous  short  spikelike  panicles  and  9-nerved  lemma,  the 
nerves  extending  into  9  equal  plumose  awns,  are  found  from  western 
Texas  to  southern  Arizona.  Pappophorum  wrightii  produces  cleis- 
togamous  spikelets  in  the  lower  sheaths.  The  cleistogenes  are  larger 
than  the  normal  florets,  but  the  awns  are  almost  wanting.  As  is  the 

1  Chase,  Amer.  Journ.  Bot.  5 :  256.     1918. 


84  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


PIG.  40. — Cottea  pappophoroides.     Plant,  X   \  ;  spikelet,  floret,  and  cleistogene  (left)  from 
axil  of  lower  leaf,  all    X    5. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES. 


85 


FIG.  41. — Pappophorum  vayinatum.     Plant,    X    i  ;  spikelet  and  perfect  floret,    X    5. 


86 


BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


case  with  other  grasses  producing  cleistogenes  in  the  lower  sheaths, 
the  culms  disarticulate  at  the  lower  nodes.    Our  species  are  of  minor 


FIG.  42. — Pappophorum  wriglitii.     Plant,    X    \  ;   spikelet,   perfect  floret,   and  cleistogene 
(below)    from  axil  of  lower  leaf,  all    X    5. 

agricultural  importance,  the  second  and  third  sometimes  constituting 
a  fair  proportion  of  the  forage  on  sterile  hills. 


GENERA  OF   GRASSES  OF  THE  UNITED  BTATES.  87 

3.  HORDEAE,  BARLEY  TRIBE. 

33.  AGBOPYBON  Gaertn. 

Spikelets  several-flowered,  solitary  (or  rarely  in  pairs),  sessile, 
placed  flatwise  at  each  joint  of  a  continuous  (rarely  disarticulating) 
rachis,  the  rachilla  disarticulating  above  the  glumes  and  between  the 
florets ;  glumes  two,  equal,  firm,  several  nerved,  usually  shorter  than 
the  first  lemma,  acute  or  awned,  rarely  obtuse  or  notched;  lemmas 
convex  on  the  back,  rather  firm,  5  to  7  nerved,  usually  acute  or  awned 
from  the  apex ;  palea  shorter  than  the  lemma. 

Perennials  or  sometimes  annuals,  often  with  creeping  rhizomes, 
with  usually  erect  culms  and  green  or  purplish,  usually  erect  spikes. 
Species  about  60,  in  the  temperate  regions  of  both  hemispheres ;  about 
25  species  in  the  United  States. 

Type  species:  Agropyron  triticeum  Gaertn. 

Agropyron  Gaertn.,  Nov.  Comm.  Acad.  Sci.  Petrop.  14:  539,  pi.  19,  f.  4.  1770. 
Gaertner  describes  two  species,  A.  cristatum,  based  on  Bromus  cristatus  L., 
and  a  new  species,  A.  triticeum.  The  second  species  is  figured.  The  species 
are  referred  by  some  authors  to  Triticum.  Some  adopt  the  spelling  Agropyrum. 

The  two  original  species  of  Agropyron  are  annuals,  but  all  the 
North  American  species  are  perennials.  Nine  of  our  species  produce 
creeping  rhizomes.  One  of  these  is  the  well-known  quack-grass  or 
couch-grass  (A.  repens  (L.)  Beauv.)  (PI.  IX;  fig.  43),  introduced 
from  Europe.  On  account  of  its  rhizomes,  it  is  a  troublesome  weed 
in  fields  and  meadows.  Quack-grass  can  be  distinguished  by  the 
glabrous,  awnless  or  short-awned  lemmas,  awn-pointed  glumes,  thin, 
flat,  usually  sparsely  pilose  blades,  and  the  yellowish  rhizomes.  An 
allied  native  species,  A.  smitJiii  Hydb.,  differs  in  its  pale  rhizomes 
and  its  firm  glaucous  blades,  soon  involute  in  drying,  the  nerves 
prominent  on  the  upper  side.  This  species,  called  western  wheat- 
grass  and  bluestem,  is  common  west  of  the  Mississippi  River,  where 
it  is  one  of  the  most  important  native  forage  grasses.  Another  com- 
mon species  of  this  group  is  A.  dasystachyum  (Hook.)  Scribn.  (in- 
cluding A.  sulvillosum  (Hook.)  E.  Nels.),  found  along  the  Great 
Lakes  and  westward. 

Of  the  species  without  rhizomes  seven  have  awnless  or  short-awned 
lemmas.  The  commonest  species  of  this  group  is  A.  tenerum  Yasey, 
called  slender  wheat-grass.  This  is  an  erect  grass  2  to  4  feet  high, 
with  flat  blades  and  slender  spikes,  the  broad  glumes  nearly  as  long 
as  the  spikelet.  It  ranges  from  New  England  to  Washington,  and 
southward  in  the  Western  States  to  Mexico.  Slender  wheat-grass 
is  an  excellent  forage  grass  and  produces  a  good  quality  of  hay.  The 
seed  is  offered  by  a  few  western  seedsmen.  This  species  is  the  only 
native  grass  that  has  been  successfully  cultivated  and  whose  seed  is 
on  the  market. 


88 


BULLETIN  772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


One  of  the  long-awned  species,  Agropyron  spicatum  (Pursh) 
Scribn.  and  Smith  (A.  divergent  Nees),  called  bunch-grass,  or  more 
distinctively  blue  bunch  wheat- 
grass,  is  of  especial  value  as  a 
forage  grass.  It  is  6ommon  in  the 
Columbia  Basin,  where  it  is  one  of 
the  chief  range  grasses.  The  spe- 
cies is  distinguished  by  its  erect 
bunchy  habit  and  by  the  spread- 
ing awns  of  the  lemmas,  giving 
the  spike  a  bristly  appearance. 


FIG.  43. — Quack-grass,  Ayropyron  repens.     Plant,   X    1 ;  spikelet,  X    3 

Two  of  our  species  have  disarticulating  spikes,  thus  approaching 
Sitanion.  These  are  Agropyron  saxicola  (Scribn.  and  Smith)  Piper, 
of  Washington,  and  A.  scribneri  Vasey,  a  spreading  mountain  species 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  IX. 


QUACK-GRASS  (AGROPYRON  REPENS). 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  X. 


BOTTLE-BRUSH  GRASS  (HYSTRIX  PATULA). 

A  native  species  worthy  of  cultivation  for  ornament. 


GENERA  OF   GRASSES   OF  THE   UNITED   STATES.  89 

found  at  altitudes  of  12,000  to  14,000  feet.  In  some  species  there  are 
two  spikelets  at  the  nodes  of  the  rachis.  This  is  especially  frequent 
in  A.  smithii  and  allies  it  with  Elymus. 

In  general,  all  the  species  of  Agropyron  are  forage  grasses.  They 
form  an  important  part  of  the  forage  on  the  western  range  and  in 
the  valleys  often  grow  in  sufficient  abundance  to  produce  hay. 

For  a  revision  of  the  species  of  Agropyron  found  in  the  United 
States,  see  Scribner  and  Smith,  U,  S.  Dept.  Agr.,  Div.  Agrost.  Bull. 

4:25-36.    1897. 

34.  TBITICUM  L. 

Spikelets  2  to  5  flowered,  solitary,  sessile,  placed  flatwise  at  each 
joint  of  a  continuous  or  articulate  rachis,  the  rachilla  disarticulating 
above  the  glumes  and  between  the  florets  or  continuous;  glumes  rigid, 
3  to  several  nerved,  the  apex  abruptly  mucronate  or  toothed  or  with 
one  to  many  awns;  lemmas  keeled  or  rounded  on  the  back,  many- 
nerved,  ending  in  one  to  several  teeth  or  awns. 

Annual,  low  or  rather  tall  grasses,  with  flat  blades  and  terminal 
spikes.  Species  about  10,  southern  Europe  and  western  Asia;  none 
in  the  United  States  except  Triticum  aestiwum,  the  cultivated  wheat. 

Type  species :  Triticum  aestivum  L. 

Triticum *  L.,  Sp.  PI.  85,  1753 ;  Gen.  PI.,  ed.  5,  37.  1754.  Linnaeus  describes 
seven  species,  T.  aestivum,  T.  hybernum,  T.  turgidum,  T.  spelta,  T.  monocoocum, 
T.  repens,  T.  caninum.  The  citation  in  the  Genera  Plantarum  is  to  Tournefort's 
figures  292  and  293  which  represent,  the  first,  beardless  wheat,  and  the  second, 
bearded  wheat.  These  two  forms,  beardless  and  bearded,  are  named  by  Lin- 
naeus T.  aestivum,  the  bearded  wheat,  and  T,  hybernum,  the  beardless  wheat. 
Triticum  aestivum  is  chosen  as  the  type  because  it  has  priority  of  position  in 
the  Species  Plantarum.  Linnseus  divides  the  genus  into  two  groups,  "  annua  " 
and  "  perennia."  The  latter  group,  including  Triticwm  repens  and  T.  caninum, 
is  now  referred  to  Agropyron. 

Zeia  Lunell,  Amer.  Midi.  Nat.  4 :  225.  1915.  Based  on  "  Triticum  spelta 
Linn."  Agropyron  Gaertn.  is  included  in  the  genus  proposed. 

The  most  important  species  of  Triticum  is  the  cultivated  wheat, 
T.  aestivum  L.  (T.  vulgare  Vill.,  T.  satiwtm  Lam.).  A  large 
number  of  varieties  are  in  cultivation,  some  with  smooth  lemmas, 
some  with  velvety  lemmas,  some  with  long  awns  (fig.  44),  some  awn- 
less  (fig.  44,  A).  Durum  wheat  and  club  wheat  are  races,  each  with 
several  varieties.  Triticum  monococcum  L.,  einkorn  or  1-grained 
wheat,  is  grown  sparingly  in  Europe.  Triticum  dicoccwm  Schrank, 
emmer,  is  cultivated  in  this  country  as  a  forage  plant.  In  emmer  the 
axis  breaks  up  into  joints,  each  joint  bearing  a  spikelet  which  re- 
mains entire,  each  floret  permanently  inclosing  its  grain.2 

1  In  the  Species  Plantarum  the  word  appears  in  the  plural,  Tritica,  probably  inadvert- 
ently. 

2  For  a  classification  of  wheats,  see  Jessen,  Deutschlands  Graser  191,  1863;  Kornicke, 
Handb.  Getreidebaues  1:  40,  1885;  Hackel  in  Engl.  and  Prantl,  Pflanzenfam.  II,  2:  80, 
1887 ;   True  Grasses,   translated  by   Scribner  and   Southworth,   180,   1890 ;   Schulz,  Mitt. 
Natf.  Ges.  Halle  1:  14.     1911.     For  an  account  of  T.  dicoccoides  Korn.,  recently  found  by 
Aaronsohn  on  Mount  Hermon,  Palestine,  see  Aaronsohn,  Verb.  Zool.  Bot.  Ges.  Wien  59: 
485,  1909;  U.  S.  Dept.  Agr.,  Bur.  PI.  Ind.  Bull.  180:  38,  1910;  Cook,  U.  S.  Dept.  Agr., 
Bur.  PI.  Ind.  Bull.  274.     1913. 


90  BULLETIN  772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  44. — Wheat,   Triticum  aestivum.     Plant  with  awned  spikes   (bearded  wheat)    and 
(A)  a  nearly  awnless  spike  (beardless  wheat),  both  X  I ;  spikelet  and  floret,  X  3. 


GENERA  OF  GRASSES  OF  THE  UNITED  STATES.  91 

35.  SECALE  L. 

Spikelets  usually  2-flowered,  solitary  and  sessile,  placed  flatwise 
against  the  rachis ;  the  rachilla  disarticulating  above  the  glumes  and 
produced  beyond  the  upper  floret  as  a  minute  stipe ;  glumes  narrow, 
rigid,  acuminate  or  subulate-pointed ;  lemmas  broader,  sharply  keeled, 
5-nerved,  ciliate  on  the  keel  and  exposed  margins,  tapering  into  a 
long  awn. 

Erect,  mostly  annual  grasses,  with  flat  blades  and  dense  terminal 
spikes.  Species  five,  in  the  temperate  regions  of  Eurasia ;  one  species 
cultivated  in  the  United  States  and  frequently  escaped  along  way- 
sides. 

Type  species :  Secale  cereale  L. 

Secale  L.,  Sp.  PI.  84, 1753 ;  Gen.  PI.  36.  1754.  Linnaeus  describes  four  species: 
S.  cereale,  S.  villosum,  S.  orientale,  and  £.  creticum.  The  second  species  is  now 
referred  to  Haynaldia,  the  third  to  Agropyron.  The  first  species  is  chosen  as 
the  type,  as  it  is  a  well-known  economic  species. 

Secale  cereale  (fig.  45),  common  rye,  is  cultivated  extensively  in 
Europe  and  to  some  extent  in  the  United  States  for  the  grain,  but 
here  it  is  frequently  grown  as  a  forage  crop.  Rye  is  used  for  winter 
forage  in  the  South  and  for  fall  and  spring  pasture  in  the  inter- 
mediate region,  and  for  green  feed  farther  north.  It  is  also  used  for 
green  manure  and  as  a  nurse  crop  for  lawn  mixtures,  especially  on 
public  grounds  when  it  is  desired  to  cover  the  ground  quickly  with  a 
green  growth.  Cultivated  rye  probably  has  been  developed  from  the 
wild  perennial  European  species  S.  montanuwi  Guss.  In  the  wild 
species  of  Secale  the  rachis  disarticulates,  but  in  8.  cereale  it  is  con- 
tinuous. 

36.  SCRIBNERIA  Hack. 

Spikelets  1-flowered,  solitary,  appressed  and  lateral  to  the  some- 
what thickened  continuous  rachis,  the  rachilla  disarticulating  above 
the  glumes,  prolonged  as  a  very  minute  hairy  stipe;-  glumes  equal, 
narrow,'  firm,  acute,  keeled  on  the  outer  nerves,  the  first  2-nerved,  the 
second  4-nerved;  floret  with  short  hairs  at  the  base;  lemma  shorter 
than  the  glumes,  membranaceous;  rounded  on  the  back,  obscurely 
nerved,  the  apex  shortly  bifid,  the  lobes  obtuse,  the  faint  midnerve 
extending  as  a  slender  straight  awn ;  palea  2-nerved,  about  as  long  as 
the  lemma. 

Low  annual,  with  slender  cylindric  spikes.     Species  one. 

Type  species :  Lepturus  bolanderi  Thurb. 

Scribneria  Hack.,  Bot.  Gaz.  11:  105,  pi.  5.  1886.  One  species  described,  based 
on  Lepturus  bolanderi  Thurb. 

The  single  species,  Scriltnerw  "bolanderi  (Thurb.)  Hack.  (fig.  46), 
is  found  in  sandy  sterile  ground  in  the  mountains  from  central 
California  to  Washington.  It  is  too  small  and  rare  to  be  of  economic 
importance. 


92  BULLETIN   772,   IT.   S.   DEPARTMENT   OF  AGRICULTURE. 


FIG.  45. — Rye,  8ecale  cereale.    Plant,  X  i  ;  spikelet,  X  3 ;  floret  showing  rudiment  back 

of  palea,   X  5. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES. 


93 


37.  ELYMUS  L. 

Spikelets  2  to  6  flowered,  sessile  in  pairs  (rarely  3  or  more  or  soli- 
tary) at  each  node  of  a  continuous  rachis,  the  florets  dorsiventral  to 
the  rachis;  rachilla  disarticulating  above  the  glumes  and  between  the 
florets;  glumes  equal,  usually  rigid,  sometimes  indurate  below,  nar- 
row, sometimes  subulate,  1  to  several  nerved,  acute  to  aristate,  some- 
what asymmetric  and  often  placed  in  front  of  the  spikelets ;  lemmas 
rounded  on  the  back  or 
nearly  terete,  obscurely 
5-nerved,  acute  or  usually 
awned  from  the  tip. 

Erect,  usually  rather  tall 
grasses,  with  flat  or  rarely 
convolute  blades  and  ter- 
minal spikes,  the  spikelets 
usually  crowded,  some- 
times somewhat  distant. 
Species  about  45,  in  the 
temperate  regions  of  the 
Northern  Hemisphere;  25 
species  in  the  United 
States,  most  of  them  in 
the  Western  States. 

Type  species :  Elymus  sibiri- 
cus L. 

Elymus  L.,  Sp.  PI.  88,  1753 ; 
Gen.  PI.,  ed.  5,  36.  1754.  Lin- 
naeus describes  five  species,  E. 
arenarius,  E.  sibiricus,  E.  can- 
adensis,  E.  virginicus,  and  E. 
c<i  put-medusae,  all  of  which 
are  still  retained  in  the  genus. 
The  first  use  of  the  name  Ely- 
mus by  Linnaeus  was  in  his 
Hortus  Upsaliensis  (1748), 
where  two  species  are  de- 
scribed, the  first  being  cited  in  the  Species  Plantarum  under  E.  virginicus 
the  second  under  E.  sibiricus.  Elymus  'sibiricus  is  chosen  as  the  type  because 
it  is  the  first  of  the  five  species  in  the  Species  Plantarum  that  is  described  in 
the  Hortus  Upsaliensis. 

Terrellia  Lunell,  Amer.  Midi.  Nat  4:  227.  1915.  Proposed  for  Elymus  L., 
not  Elymus  of  various  ancient  authors. 

The  asymmetric  glumes,  in  many  species  standing  in  front  of  the 
spikelet  instead  of  strictly  distichous  and  in  some  species  united  at 
the  very  base,  have  been  the  object  of  investigations  as  to  their 
morphological  identity.  Schenck1  considers  them,  to  be  developed 
from  lateral  branches  at  the  base  of  the  spikelet.  Schuster2  states 
that  the  first  or  outer  glume  originates  as  a  single  organ  but  soon 


FIG.  46. — Scribneria  bolanderi. 
let  with  joint  of  rachis,  X 
view,  X  5. 


Plant,    X    I  ;   spike- 
5 ;    the   same,    front 


iRot.    Jahrb.    Engler   40:    97-113.      1907. 
3  Flora  100:  213-266,  pi.  2-5.     1910. 


94  BULLETIN   772,   U.   S.   DEPARTMENT  OF   AGRICULTURE. 

divides  into  two  parts,  which  stand  side  by  side  below  the  spikelet, 
the  second  glume  being  suppressed. 

In  the  group  of  Elymm  virginicus  L.  and  its  allies  the  glumes  are 
indurate  at  the  base  and  bowed  out.  They  stand  in  front  of  the 
spikelet  rather  than  at  each  side,  so  that  the  contiguous  glumes  of 
the  pair  of  spikelets  are  not  back  to  back  but  side  by  side.  In 
E.  arenarius  L.,  E.  glaucus  Buckl.,  and  allied  species,  the  glumes  are 
less  distinctly  in  front  of  the  spikelets.  The  rachis  of  the  spike  is 
usually  continuous  but  in  E.  saundersii  Vasey,  and,  to  a  less  extent,  in 
E.  macounii  Vasey,  the  rachis  disarticulates,  showing  a  transition 
to  Sitanion.  In  many  species,  such  as  E.  simplex  Scribn.  and  Merr., 
and  E.  salina  Jones  (named  from  Salina  Pass),  the  middle  spikelets 
are  in  pairs,  but  those  toward  the  base  and  apex  of  the  spike  are 
single  at  the  nodes.  Such  species  are  a  transition  to  Agropyron. 
On  the  other  hand  Agropyron  smithii  often  has  one  or  more  pairs 
of  spikelets  and  may  be  considered  a  transition  to  Elymus.  But  in 
the  former  species  the  glumes  are  narrow  or  almost  subulate,  which 
shape  is  to  be  found  in  Elymus  rather  than  in  Agropyron.  The 
spikelets  are  usually  not  more  than  two  at  each  node  of  the  rachis, 
but  in  E.  trlticoides  Buckl.  there  are  often,  and  in  E.  condensatus 
Presl.  usually,  more  than  two  spikelets  at  each  node.  Sometimes  in 
the  latter  species  (rarely  in  the  former)  the  spike  is  branched  so 
that  the  inflorescence  is  a  condensed  panicle  instead  of  a  spike. 
Elymus  caput-medusae  L.  is  an  annual  introduced  from  Europe ;  the 
other  species  are  native  perennials.  Some  species  form  extensively 
creeping  rhizomes,  such  as  Elymus  mollis  Trin.,  of  the  sandy  sea- 
coasts  of  northern  North  America,  E.  flavescens  Scribn.  and  Smith, 
of  the  interior  dunes  of  the  Columbia  River  basin,  and  E.  triticoides 
Buckl.,  of  alkaline  soil  of  the  Western  States.  Elymus  canad^msis  L. 
(fig.  47)  and  E.  virginicus,  usually  called  wild  rye,  are  common  in 
the  eastern  half  of  the  United  States.  The  first  has  a  bushy  nodding 
head ;  the  latter  an  erect,  stiff  head. 

The  species  of  Elymus  are  for  the  most  part  good  forage  grasses, 
and  in  some  localities  form  a  part  of  the  native  hay.  In  the  wooded 
areas  of  the  Northwest,  E.  glcaivus  Buckl.  is  one  of  the  valuable  sec- 
ondary species  on  the  ranges.  It  has  flat,  thin  leaves,  erect  awned 
spikes,  broad  glumes,  and  no  rhizomes. 

38.  SITANION  Raf. 

Spikelets  2  to  few  flowered,  the  uppermost  floret  reduced,  sessile, 
usually  2  at  each  node  of  a  disarticulating  rachis,  the  rachis  break- 
ing at  the  base  of  each  joint,  remaining  attached  as  a  pointed  stipe 
to  the  spikelets  above;  glumes  narrow  or  setaceous,  1  to  3  nerved, 
the  nerves  prominent,  extending  into  one  to  several  awns,  these 
(when  more  than  one)  irregular  in  size,  sometimes  mere  lateral 


GENERA  OF   GRASSES  OF  THE   UNITED  STATES. 


95 


Fio.  47. — Wild  rye,  Elymus  canadenais.    Plant,   X   5  ;  splkelet  and  floret,   X   3. 


98  BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 

Erect  perennials,  with  flat  blades  and  bristly,  loosely  flowered 
spikes.  Species  four,  in  temperate  regions;  one  in  the  Himalayas, 
one  in  New  Zealand,  and  two  in  the  United  States. 

Type  species:  Elymus  hystrix  L. 

Asperella  Humb.,  Magaz.  Bot.  Roem.  and  Usteri  7:  5,  1790,  not  Asprella 
Schreb.,  1789,  a  typonym  of  Homalocenchrus  Mieg.  A  single  species,  A.  hystrix, 
based  on  Elymus  hystrix  L. 

Hystrix  Moench,  Meth.  PI.  294.  1794.  One  species  described,  H.  patula, 
based  on  Elymus  hystrix  L. 

Gymnostichum  Schreb.,  Beschr.  Gras.  3:  127,  pi.  47.  1810.  One  species  de- 
scribed, G.  hystrix,  based  on  Elymus  hystrix  L. 

Our  species  are  both  woodland  grasses,  one,  Hystrix  patula  Moench 
(H.  hystrix  (L.)  Millsp.)  (PL  X;  fig.  49),  in  the  Mississippi  Valley 
and  eastward;  the  other,  H.  calif 'arnica  (Boland.)  Kuntze,  in  western 
central  California.  They  have  little  forage  value,  as  they  are  no- 
where abundant.  The  first  species  mentioned,  sometimes  called 
bottle-brush  grass,  is  worthy  of  cultivation  for  ornament. 

40.  HORDEUM  L. 

Spikelets  1 -flowered,  3  (sometimes  2)  together  at  each  node  of  the 
articulate  rachis  (continuous  in  Hordeum  vulgare}^  the  back  of 
the  lemma  turned  from  the  rachis,  the  middle  one  sessile  or  sub- 
sessile,  the  lateral  ones  pediceled;  rachilla  disarticulating  above  the 
glumes  and,  in  the  central  spikelet,  prolonged  behind  the  palea  as  a 
bristle  and  sometimes  bearing  a  rudimentary  floret;  lateral  spikelets 
usually  imperfect,  sometimes  reduced  to  bristles ;  glumes  narrow,  often 
subulate  and  awned,  rigid,  standing  in  front  of  the  spikelet ;  lemmas 
rounded  on  the  back,  5-nerved,  usually  obscurely  so,  tapering  into  a 
usually  long  awn. 

Annual  or  perennial  low  or  rather  tall  grasses,  with  flat  blades  and 
dense  terminal  cylindric  spikes.  Species  about  20,  in  the  temperate 
regions  of  both  hemispheres ;  10  species  in  the  United  States,  3  being 
introduced  from  Europe. 

Type  species:  Hordeum  vulgare  L. 

Hordeum  L.,  Sp.  PI.  84,  1753;  Gen.  PI.,  ed.  5,  37.  1754.  Linnaeus  describes 
six  species,  H.  vulgare,  H.  hexastichon,  H.  distichon,  H.  zeocriton,  H.  murinum, 
and  H.  jubatum.  The  citation  given  in  the  Genera  Plantarum  is  to  Tourne- 
fort's  plate  295,  which  represents  Hordeum  vulgare.  This  species  is  therefore 
the  type.  All  the  Linnsean  species  are  retained  in  the  genus  at  present,  but  the 
first  four  are  usually  considered  to  be  forms  of  one  species. 

Zeocriton  Beauv.,  Ess.  Agrost.  114,  pi.  21,  f.  2.  1812.  Ten  species  of 
Hordeum  having  staminate  or  sterile  lateral  spikelets  are  included ;  H.  distichum, 
the  species  figured,  is  taken  as  the  type. 

Critesion  Raf.,  Journ.  de  Phys.  89:  103.  1819.  A  single  species  is  described, 
C.  genicula-tus  Raf.  This  is  Hordeum  jubatum  L. 

The  most  important  species  of  the  genus  is  Hordeum  vulgare  (fig. 
50),  the  cultivated  barley.  This  is  an  annual,  resembling  bearded 
wheat,  the  awns  as  much  as  6  inches  long.  In  common  or  4-rowed 
barley  the  3  spikelets  of  each  cluster  are  fertile,  the  lateral  spikelets  of 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  99 

the  opposite  sides  of  the  spike  being  imbricate  in  a  row,  so  that  the 
spike  appears  to  be  4-rowed.    In  6-rowed  barley  (H.  hexastichon  L.) 


FIG.  49. — Bottle-brush  grass,  Hystrix  patula.     Plant,    X    »  ;  spikelet  and  floret,    X    3. 

the  lateral  spikelets  form  rather  distinct  rows.     In  2-rowed  barley 
(H.  distichon  L.)  the  lateral  spikelets  are  all  infertile  and  reduced, 


100  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


Fio.  50. — Barley,  Hordeum  vulgare.  Plant,  X  i  ;  A,  a  spike  of  beardless  barley,  X  i  I 
group  of  three  spikelets  and  a  floret,  the  latter  showing  the  rudiment  back  of  the 
palea,  X  3. 


GENERA  OF   GRASSES   OF  THE   TTFr^O   SJ/ATES.  101 

so  that  only  the  row  of  central  spikelets  on  undi-sido  'oi  tfe  spike  is 
prominent.  Naked  barley  is  a  kind  of  2-rowed  barley  in  which  the 
grain  is  free  from  the  lemma  and  palea.  Rice  barley  (H.  zeocriton 
L.),  with  spreading  spikelets  and  divergent  awns,  is  not  grown  in  this 
country  and  but  sparingly  in  Europe.  Beardless  barley  (H.  vulgare 
trifurcatum  Wenderoth)  (fig.  50,  A)  is  a  variety  of  6-rowed  barley 
in  which  the  awns  are  suppressed  or  converted  into  irregular  short 
lobes  or  teeth.  Schulz1  divides  the  cultivated  barleys  into  two 
groups.  The  first  group,  derived  from  II.  spontomeum  Koch,  in- 
cludes the  2-rowed  varieties.  The  second  group,  derived  from  H. 
ischnatherum  (Coss.)  Schulz,  includes  the  4  and  6  rowed  varieties. 
The  glumes  of  Hordeum  are  thought  by  Schenck  to  be  sterile  spike- 
lets  or  branchlets.  (See  footnote  under  Elymus,  p.  93.) 

Three  common  species  of  Hordeum  are  annuals.  One  of  these, 
II.  pusillum  Nutt.,  with  glumes  broadened  above  the  base,  is  a  native 
species.  The  other  two,  introduced  from  Europe,  are  common  weeds  on 
the  Pacific  coast.  In  77.  murmum,  L.  a  part  of  the  glumes  are  ciliate ; 
in  II.  gussoneanum  Parl.  the  glumes  are  setaceous,  smooth  below. 
Hordeum  nodosum  L.  (fig.  51)  is  similar  to  PI.  pusillum  but  differs 
in  being  perennial  and  in  having  uniformly  subulate  glumes.  This 
species  is  abundant  throughout  the  western  half  of  the  United  States. 
Another  perennial  species,  H.  jubatum  L.,  called  squirreltail  grass 
because  of  its  soft  brushlike  spikes,  is  common  in  the  Western  States, 
where  it  is  not  infrequently  a  troublesome  weed  in  alfalfa  fields. 
This  species  is  called  foxtail  in  Wyoming,  barley  grass  in  Utah,  and 
tickle  grass  in  Nevada.  Hordeum,  murinum^  mentioned  above,  is 
called  barley  grass,  foxtail,  and  wild  barley  in  different  localities. 

The  species  of  Hordeum  furnish  forage  during  the  early  stages  of 
growth  before  the  awns  are  produced.  The  mature  spikes  break  up 
into  sharp-pointed  joints  that  become  a  serious  pest  to  stock.  These 
joints  with  the  forwardly  roughened  awns  work  into  the  eyes  and 
nostrils  of  animals,  causing  inflammation. 

For  a  revision  of  the  species  of  Hordeum  found  in  the  United 
States,  see  Scribner  and  Smith,  U.  S.  Dept.  Agr.,  Div.  Agrost.  Bull. 
4:23-25.  1897. 

41.  LOLIUM  L. 

Spikelets  several-flowered,  solitary  and  sessile,  placed  edgewise  to 
the  continuous  rachis,  one  edge  fitting  to  the  alternate  concavities,  the 
rachilla  disarticulating  above  the  glumes  and  between  the  florets ;  first 
glume  wanting  (except  on  the  terminal  spikelet),  the  second  outward, 
strongly  3  to  5  nerved,  equaling  or  exceeding  the  second  floret ;  lemmas 
rounded  on  the  back,  5  to  7  nerved,  obtuse,  acute,  or  awned. 

iMitt.  Natf.  Ges.  Halle  1:  18.     1911. 


102          BULLETIN   772>    U.   3.   DEPARTMENT   OF   AGRICULTURE. 


FIG.  51. — Hordeum  nodosum.     Plant,    X    I.  ;  group  of  three   spikelets  with  rachis  joint 
attached  and  a  floret,  the  latter  showing  the  rudiment  back  of  the  palea,    X    3. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  103 

Annuals  or  perennials,  with  flat  blades  and  simple  terminal  flat 
spikes.  Species  about  eight,  in  Eurasia,  four  of  these  being  intro- 
duced in  the  United  States. 

Type  species :  Lolium  perenne  L. 

Lolium  L.,  Sp.  PI.  83,  1753 ;  Gen.  PL,  ed.  5,  36.  1754.  Linnaeus  describes  two 
species,  L.  perenne  and  L.  temulentum.  The  first  is  chosen  as  the  type,  as  it  is 
an  economic  species.  Both  were  described  in  the  flora  of  Sweden. 

Two  species  are  of  agricultural  importance.  Lolium  perenne,  Eng- 
lish or  perennial  rye-grass,  was  the  first  meadow  grass  to  be  culti- 
vated in  Europe  as  a  distinct  segregated  species,  the  meadows  and 
pastures  formerly  being  mixed  native  species.  This  and  the  next  are 
probably  the  most  important  of  the  European  forage  grasses.  Eng- 
lish rye-grass  is  a  biennial  or  short-lived  perennial,  2  to  3  feet  tall, 
with  glossy  dark-green  leaves  and  a  slender  spike  as  much  as  a  foot 
long,  the  spikelets  8  to  10  flowered,  somewhat  longer  than  the  glume, 
the  lemmas  awnless.  Italian  rye-grass,  L.  multiflorum  Lam.  (L.  itali- 
cum  A.  Br.)  (PL  XI;  fig.  52),  differs  from  the  preceding  in  having 
awned  lemmas  and  usually  a  greater  number  of  florets  to  the  spikelet. 
Both  species  are  used  to  a  limited  extent  for  meadow,  pasture,  and 
lawn.  They  are  of  some  importance  in  the  South  for  winter  forage. 
Lolium  multiftorum  is  common  in  the  humid  region  of  the  Pacific 
coast,  where  it  is  often  called  Australian  rye-grass. 

In  the  Eastern  States  the  rye-grasses  are  often  sown  in  mixtures 
for  parks  or  public  grounds,  where  a  vigorous  early  growth  is  re- 
quired. The  young  plants  can  be  distinguished  from  bluegrass  by  the 
glossy  dark-green  foliage. 

Lolium  temulentum  L.,  darnel,  is  occasionally  found  as  a  weed  in 
grain  fields  and  waste  places.  It  is  in  bad  repute,  because  of  the  pres- 
ence in  the  fruit  of  a  narcotic  poison,  said  to  be  due  to  a  fungus.  Dar- 
nel is  supposed  to  be  the  plant  referred  to  as  the  tares  sown  by  the 
enemy  in  the  parable  of  Scripture.  It  is  an  annual,  with  glumes  as 
much  as  an  inch  long  and  exceeding  the  5  to  7  florets. 

42.  LEPTURUS  R.  Br. 
(Monerma  Beauv.) 

Spikelets  1-flowered,  embedded  in  the  hard,  cylindric,  articulate 
rachis,  placed  edgewise  thereto,  the  first  glume  wanting  except  on  the 
terminal  spikelet,  the  second  glume  closing  the  cavity  of  the  rachis 
and  flush  with  the  surface,  indurate,  nerved,  acuminate,  longer  than 
the  joint  of  the  rachis ;  lemma  lying  next  the  rachis,  hyaline,  shorter 
than  the  glume,  3-nerved ;  palea  hyaline,  2-nerved,  a  little  shorter  than 
the  lemma;  rachilla  not  disjointing,  the  spikelet  falling  entire,  at- 
tached to  its  rachis  joint. 

Low  annuals  or  perennials,  with  hard  cylindric  spikes.  Species 
three,  all  from  the  Eastern  Hemisphere,  one  introduced  in  California. 


104          BULLETIN  772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  52.— Italian  rye-grass,  Lolium  multifiorum.     Plant,   X    I  ;  spikelet,   X  3  ;  floret,   X  5. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XI, 


ITALIAN  RYE-GRASS  (LOLIUM  MULTIFLORUM). 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XII. 


TALL  OAT-GRASS  (ARRHENATHERUM  ELATIUS). 


GENEKA  OF   GRASSES   OF   THE  UNITED  STATES. 


105 


Type  species :  Rottboellia  repcns  Forst. 

Lepturus  R.  Br.,  Prodr.  Fl.  Nov.  Holl.  207.     1810.     One  species  described   L 
repens,  based  on  Rottboellia  repens  Forst. 


Monerma  Beauv., 
Ess.  Agrost.  116, 
pi.  20,  f.  10.  1812. 
The  species  figured 
is  M .  monandra, 
which  is  Lepturus 
cylindrica. 

Leptocercus  Raf., 
Amer.    Monthly 
Mag.  4:  190.    1819. 
In    a    review    of    Nuttall's 
Genera    Rafinesque   changes 
the  name  Lepturus  R.  Br.  to 
Leptocercus    because    of    a 
genus  of  insects  by  the  name 
of  Leptura. 

Our  one  species,  Lep- 
turus  cylindrica  (Willd.) 
Trin.  (fig.  53),  is  intro- 
duced in  salt  marshes 
from  San  Francisco  to 
San  Diego.  At  matur- 
ity the  spike  breaks  up 
into  the  1 -seeded  joints. 
The  species  has  no  eco- 
nomic value.  For  other 
species  that  have  been 
referred  to  Lepturus.  see 
Pholiurus. 

43.  PHOLIURUS   Trin. 
(Lepturus  of  authors,  not 
R.  Br.) 

Fie.    ^.-Lcvturus    cylinartca.      Plant,     X     1'          ^pikelets  1   or   2   HOW- 
spikelet  with  a  joint  of  the  rachis,  x  5 ;  spike-     erecl?     embedded     in     the 

let,  front  view,  x  5.  articulate    rachis    and 

falling  attached  to  the  joints;  glumes  two,  placed  in  front  of  the 
spikelet  and  inclosing  it,  coriaceous,  5-nerved,  acute,  asymmetric, 


106 


BULLETIN   772,   U.   S.   DEPARTMENT  OF   AGRICULTURE. 


appearing  like  halves  of  a  single  split  glume ;  lemma  lying  next  to  the 
axis,  smaller  than  the  glumes,  hyaline,  keeled,  scarcely  more  than 
1-nerved ;  palea  a  little  shorter  than  the  lemma,  hyaline,  2-nerved. 

Low  annuals,  with  cylindric  spikes.  Species  four,  in  the  Eastern 
Hemisphere,  one  introduced  into  the  United  States. 

Type  species :  Roffboellia  pannonica  Host. 

Pholiurus  Trin.,  Fund.  Agrost.  131.  1820.  Based  on  a  single  species.  Rott- 
boellia  pannonica  Host.  This  species  has  2-flowered  spikelets. 

Lepiurus  Dumort.,  Obs.  Gram.  Beige  140,  pi.  15,  f.  57.  1823.  A  single  species 
based  on  "  Rottbolia  incurvata  L."  fils. 

The  species  of  Pholiurus  have  been  referred  by  most  recent  authors 
to  Lepturus,  the  type  of  which  was,  by 
the  same  authors;  referred  to  Monerma. 

Our  species,  Pholiurus  incurvatus  (L) . 
Hitchc.  (Aegilops  incurvata  L.,1  Lep- 
turus  filiformis  (Eoth.)  Trin.)  (fig.  54), 
has  1-flowered  spikelets.  It  is  intro- 
duced along  the  borders  of  salt  marshes 


FIG.  54. — Pholiurus  incur  vatuti.     Plant,   x    i  ;  spikelet  with  a  joint  of  the  rachis,   X   5 ; 

spikelet,  front  view,   X  5. 

from  Maryland  to  Virginia  and  from  Marin  County  to  San  Diego, 
Calif.     It  has  no  economic  value. 

4.  AVENEAE,  THE  OAT  TRIBE. 

44.  KOELERIA  Pers. 

Spikelets  2  to  4  flowered,  compressed,  the  rachilla  disarticulating 
above  the  glumes  and  between  the  florets,  prolonged  beyond  the  per- 
fect florets  as  a  slender  bristle  or  bearing  a  reduced  or  sterile  floret  at 
the  tip ;  glumes  usually  about  equal  in  length  but  unequal  in  shape, 
the  lower  narrow  and  sometimes  shorter,  1-nerved,  the  upper  some- 
what broader  above  the  middle,  wider  than  the  lower,  3  to  5  nerved ; 


1  Sp.  PI.  ed.  2.  2:  1490.     1763. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  107 

lemmas  somewhat  scarious  and  shining,  the  lowermost  a  little  longer 
than  the  glume,  obscurely  5-nerved,  acute  or  short-awned,  the  awn, 
if  present,  borne  just  below  the  apex. 

Annual  or  perennial,"  slender,  low  or  rather  tall  grasses,  with  nar- 
row blades  and  spikelike  panicles.  Species  about  20,  in  the  temperate 
regions  of  both  hemispheres;  two  species  in  the  United  States,  one 
native  and  one  introduced. 

Type  species :  Aira  cristata  L. 

Koeleria  Pers.,  Syn.  PI.  1 : 97.  1805,  Persoon  describes  five  species,  K.  yra- 
cilis,  K.  cristata,  K.  tuberosa,  K.  phleoides,  and  K.  villosa.  Of  these,  K.  cristata 
and  K.  phleoides  were  described  by  Linnaeus,  the  first  under  Aira,  the  second 
under  Festuca.  The  first  of  these  is  selected  as  the  type,  as  it  has  priority  of 
position  in  the  Species  Plantarum. 

Airochloa  Link,  Hort.  Berol,  1 : 126.  1827.  Six  species  are  included.  Koeleria 
cristata,  upon  which  the  first  species  is  based,  is  taken  as  the  type. 

Brachystylus  Dulac,  Fl.  Hautes  Pyr.  85.    1867.    Based  on  "  Koeleria  Pers." 

Recently  a  monograph  of  Koeleria  was  published  by  Domin1  in  which  many 
species  were  described.  Several  of  these  were  based  upon  material  from  the 
United  States  but  appear  to  be  only  forms  of  the  widely  distributed  K.  cristata. 

Koeleria  cristata  (L.)  Pers.  (fig.  55)  is  the  only  species  native  in 
North  America.  This  is  a  common  constituent  of  grassland  on  prai- 
ries, plains,  and  in  open  woods  from  Ontario  to  British  Columbia  and 
south  to  northern  Mexico.  It  is  a  cespitose  perennial,  with  slender, 
erect  culms  a  foot  or  two  high,  with  a  pale,  shining,  densely  flowered 
panicle  2  to. 5  inches  long.  The  species  varies  much,  but  the  forms, 
except  K.  cristata  longifolia  Yasey,  of  California,  with  longer  blades 
and  larger,  more  open  panicles,  can  not  be  distinguished  as  varieties. 
The  slender  form,  of  the  semiarid  plains  and  foothills  of  the  West, 
is  held  by  some  as  distinct  and  called  K.  grocilis  Pers.  The 
spikelets  of  K.  cristata  are  mostly  2  or  3  flowered,  with  a  slender 
prolongation  of  the  rachilla,  and  the  lemmas  are  acute  or  mucronate, 
but  not  awned.  The  habit  suggests  a  species  of  Poa,  from  which 
genus  it  is  distinguished  by  its  mostly  2  or  3  flowered  spikelets,  acute 
lemmas,  and  the  culm  puberulent  below  the  panicle.  A  second 
species,  K.  phleoides  (Vill.)  Pers.,  a  low  annual  with  short-awned 
lemmas,  is  introduced  from  Europe  in  a  few  localities.  Hackel  (Nat. 
Pfl anzenf am. )  places  Koeleria  in  the  FestuceaB,  but  South  American 
and  Old  World  species  of  Koeleria,  with  lemmas  awned  below  the 
apex,  as  well  as  the  shining  culm  and  spikelets  of  K.  cristata^  show 
clearly  an  affinity  to  Trisetum.  For  this  reason  the  genus  is  here 
placed  in  Aveneae,  although  the  glumes  do  not  exceed  the  florets  as 
they  do  in  nearly  all  the  Aveneae. 

Koeleria  cristata  is  a  good  forage  grass  and  is  a  constituent  of 
much  of  the  native  pasture  throughout  the  Western  States. 

45.  TRISETUM  Pers. 

Spikelets  usually  2-flowered,  sometimes  3  to  5  flowered,  the  rachilla 
prolonged  behind  the  upper  floret,  usually  villous ;  glumes  somewhat 

1  Monographic  der  Gattung  Koeleria.     1907. 


108          BULLETIN   772,   TJ.   S.   DEPARTMENT  OF  AGRICULTURE. 


unequal,  acute,   awnless,  the  second  usually   longer  than  the  first 
floret;  lemmas  usually  short-bearded  at  the  base,  2-toothed  at  the 

apex,  the  teeth  often  awned,  bear- 
ing from  the  back  below  the 
cleft  apex  a  straight  and  in- 
cluded, or  usually  bent  and  ex- 
serted,  awn. 

Tufted  perennials  with  flat 
blades  and  open  or  usually  con- 
tracted or  spikelike  panicles. 
Species  about  65,  in  the  arctic 
and  temperate  regions  of  both 
hemispheres ;  eight  species  in  the 
United  States,  mostly  in  the 
mountains. 

Type  species :  Arena  flavescens  L. 

Trisetum  Pers.,  Syn.  PI.  1: 97.  1805. 
Persoon  describes  11  species.  The 
seventh  species,  T.  pratense  Pers., 
based  on  Avena  flavescens  L.,  is  chosen 
as  the  type,  because  it  is  historically 
the  oldest  species. 

Graphephorum  Desv.,  Nouv.  Bull. 
Soc.  Philom.  Paris  2:  189.  1810. 
Based  on  Aira  melicoides  Michx. 

The  name  Trisetum  refers  to 
the  three  awns  on  the  lemma  of 
many  of  the  species,  one  from  the 
back  and  one  from  each  of  the 
teeth.  In  two  of  our  species,  T. 
melicoideum  (Michx.)  Scribn. 
and  T.  wolfii  Vasey,  the  awn 
from  the  back  is  included  within 
the  glume  or  is  wanting.  Trise- 
tum spicatum  (L.)  Eichter  (fig. 
56)  is  found  at  high  altitudes  in 
all  the  western  mountains  and  is 
widespread  at  high  altitudes  and 
in  the  arctic  regions  of  the  North- 
ern Hemisphere.  It  is  an  erect 
grass  with  a  spikelike,  often 
dark-colored  panicle,  the  awn 
exserted  and  bent.  Trisetum 
canes cens  BuckL,  of  the  Western 
States,  is  a  woodland  grass  with 
narrow  but  rather  loose  panicles.  Trisetum  cernuum  Trin.,  of  the 
Northwest,  has  broad  flat  blades  and  a  loose  open  penicle,  with  lax 


FIG.  55. — Koeleria   cristata. 
spikelet  and  floret, 


Plant, 
X   5. 


X    I 


GENERA  OF  GRASSES  OF  THE   UNITED  STATES. 


109 


drooping  branches,  the  florets  distant  in  the  usually  3-flowered  spike- 
lets.   Trisetum pennsylvanicum  (L.)  Roem.  and  Schult.  (Sphenopholis 

palustris  (Michx.) 
Scribn.),  T.  hallii 
Scribn.,  and  T.  inter- 
ruptum  Buckl.  have 
been  referred  to 
Sphenopholis.  I  n 
the  first,  the  upper 
lemma  is  slightly 
bearded  at  base,  the 
lower  glabrous ;  in 
the  other  two,  the 
lemmas  are  glabrous. 
In  these  three  species 
the  articulation  is  be- 
low the  spikelet,  as  in 
Sphenopholis,  for 
which  reason  Scrib- 
ner  placed  them  in 
that  genus,  but  their 
a  w  n  e  d,  relatively 
thin  lemmas  and 
their  glumes  alike  in 
shape  place  them 
more  naturally  in 
Trisetum. 


FIG.  56. — Trisetum  spicatum.     Plant,    X    I  ;   spikelet  and  floret,    X    5. 

The  species  of  Trisetum  are  all  valuable  for  grazing.     Trisetum 
spicatum  constitutes  an  important  part  of  the  forage  on  alpine  slopes. 


110          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

46.  SPHEXOPHOLIS  Scribn. 
(Eatonia  of  authors,  not  Raf.) 

Spikelets  2  or  3  flowered,  the  pedicel  disarticulating  below  the 
glumes,  the  rachilla  produced  beyond  the  upper  floret  as  a  slender 
bristle ;  glumes  unlike  in  shape,  the  first  narrow,  acute,  1-nerved,  the 
second  broadly  obovate,  3  to  5  nerved,  somewhat  coriaceous;  lemmas 
firm,  scarcely  nerved,  awnless,  the  first  a  little  shorter  or  a  little 
longer  than  the  second  glume. 

Perennial  grasses,  with  usually  flat  blades  and  narrow  panicles. 
Species  four,  in  the  United  States,  extending  into  Mexico  and  the 
West  Indies. 

Type  species:  Aim  obhifuita  Miehx. 

Reboulea  Kunth,  Rev.  Gram.  1:  341,  pi.  84,  1830,  not  Rebouillia  Raddi,  1818. 
A',  gracilis,  the  only  species  described,  is  the  same  as  Aira  obtusata  Michx. 

Colobanthus  (Trin.)  Spach.  Suites  Buff.  13:  163,  1846,  not  Bartl.,  1830. 
Trinius  applied  the  name  to  a  section  of  Trisetum.  The  type  is  Koeleria  penn- 
sylvanica  DC.  (Sphenopholis  pallens),  the  first  of  two  species  mentioned  by 
Trinius,  the  other  being  Aira  obtiisata  Michx. 

Sphenopholis  Scribn.,  Rhodora  8 : 142.  1906.  A  new  name  is  proposed  for  the 
group  of  grasses  then  known  as  Eatonia,  and  the  type  species  is  designated. 
Scribner  showed  that  the  original  description  of  Eatonia  Raf.  could  not  apply 
to  the  genus  as  later  described  by  Endlicher.1  The  type  species  of  Eatonia  Raf. 
proves  to  be  Panicum  virgatum.2  The  genus  Sphenopholis  was  revised  by  Scrib- 
ner in  the  above-mentioned  paper. 

One  species,  Sphenopholis  obtwata  (Michx.)  Scribn.  (fig.  57),  is 
widespread,  but  not  very  abundant,  throughout  the  eastern  half  of 
the  United  States.  In  the  western  portion  of  its  range  the  panicle  is 
condensed  and  spikelike  (var.  lolata  (Trin.)  Scribn.).  All  the 
species  are  forage  grasses,  but  they  are  usually  not  abundant  enough 
to  be  of  much  importance. 

47.  AVENA  L.,  oats. 

Spikelets  2  to  several  flowered,  the  rachilla  bearded,  disarticulating 
above  the  glumes  and  between  the  florets ;  glumes  about  equal,  mem- 
branaceous  or  papery,  several-nerved,  longer  than  the  lower  floret, 
usually  exceeding  the  upper  floret ;  lemmas  indurate,  except  toward 
the  summit,  5  to  9  nerved,  bidentate  at  the  apex,  bearing  a  dorsal  bent 
and  twisted  awn  (this  straight  and  reduced  in  Avena  sativa). 

Annual  or  perennial,  low  or  moderately  tall  grasses,  with  narrow  or 
open,  usually  rather  few-flowered  panicles  of  usually  large  spikelets. 
Species  about  55,  in  the  temperate  regions;  only  a  few  in  the  Western 
Hemisphere;  7  species  in  the  United  States,  only  2  being  native. 

Type  species :  Avena  sativa  L. 

Avena  L.,  Sp.  PI.  79,  1753;  Gen.  PI.,  ed.  5,  34.  1754.  Linnaeus  describes  10 
species,  3  of  which  are  now  retained  in  Avena.  These  are  A.  sativa,  A.  fatiia, 
and  A.  pratensis.  The  other  species  are  now  referred  as  follows :  A.  sibirica  to 

.  PI.  99.     1837.  2  Hitchcock,  Contr.  U.  S.  Nat  Herb.   15:87.     1910. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES. 


Ill 


Stipa,  A.  elatior  to  Arrhenatherum,  A.  pennsylvanica  to  Trisetum,  A.  flavescens 
to  Trisetum,  A.  fra'gilis  to  Gaudinia,    A.,spicata  to  Danthonia.     In  the  Genera 


FIG.  57. — Sphenopholis  obtusata.     Plant,    X    i  ;  spike- 
let  and  floret,   X   5. 


Plantarum,  Linnaeus  cites 
Tournefort's  figure  26  f 
(error  for  297),  which  is 
Avena  sat  iva,.  Hence 
this  is  the  type  species. 

The  most  impor- 
tant species  of  the 
genus  is  Avena  sativa, 
the  familiar  culti- 
vated oat.  In  many 
of  the  varieties  the 
awn  is  straight,  often 
reduced,  or  even  want- 
ing. The  spikelets 
contain  usually  two 
florets  that  do  not 
easily  disarticulate. 
The  lemmas  are 
smooth  or  slightly 
hairy  at  the  base,  the 
apical  teeth  acute  but 
not  awned.  The  grain 
is  permanently  in- 
closed in  the  lemma 
and  palea.  Two  other 
introduced  species  are 
known  as  wild  oats, 
because  of  their  close 
resemblance  to  the 
cultivated  oat.  Avena 
fatua  L.  (fig.  58)  dif- 
fers from  A.  sativa 
in  the  readily  disar- 
ticulating florets,  be- 
set with  stiff,  usually 
brown  hairs,  and  in 

£he   well-developed 


.      .    J 

geniculate  and  twisted 
awn.     A  variety  of  this  (A.  fatua  glalrata  Peterm.)  has  glabrous 


112  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

florets.     In  our  other  species  of  wild  oats,  A.  barbata  Brot.,  the 
pedicels  are  more  slender,  the  spikelets  pendulous,  and  the  teeth  of 


FIG.  58. — Wild  oats,  Avena  fatua.     Plant,    X    I  ;  spikelet  and  floret,    X    2. 

the  lemma  are  prolonged  into  delicate  awns.     These  species  of  wild 
oats  are  common  on  the  Pacific  coast,  where  they  are  weeds,  but  are 


GENEKA  OF   GRASSES   OF  THE   UNITED  STATES.  113 

utilized  for  hay.  Much  of  the  grain  hay  of  that  region  is  made  from 
either  cultivated  or  wild  oats. 

The  varieties  of  cultivated  oat  are  derived  from  three  species  of 
Avena.  The  common  varieties  of  this  country  and  of  temperate  and 
mountain  regions  in  general  are  derived  from  A.  faitua.  The 
Algerian  oat  grown  in  North  Africa  and  Italy  and  the  red  oat  of  our 
Southern  States  are  derived  from  A.  sterUis.  A  few  varieties 
adapted  to  dry  countries  are  derived  from  A.  bar'bata'*-. 

Avena  sterilis  L.,  animated  oats,  is  sometimes  cultivated  as  a 
curiosity.  When  laid  on  the  hand  or  other  moist  surface  the  fruits 
twist  and  untwist  as  they  lose  or  absorb  moisture. 

Our  two  native  species,  found  in  the  Rocky  Mountain  region,  are 
perennials,  with  narrow  few-flowered  panicles  of  erect  spikelets 
smaller  than  those  of  Avena  sativa.  They  are  excellent  forage 
grasses,  but  occur  only  scatteredly. 

48.  AREHENATHERUM  Beauv. 

Spikelets  2-flowered,  £he  lower  floret  staminate,  the  upper  perfect, 
the  rachilla  disarticulating  above  the  glumes,  produced  beyond  the 
florets  as  a  slender  bristle ;  glumes  rather  broad  and  papery,  the  first 
1-nerved,  the  second  a  little  longer  than  the  first  and  about  as  long 
as  the  spikelet,  3-nerved;  lemmas  5-nerved,  hairy  on  the  callus,  the 
lower  bearing  near  the  base  a  twisted,  geniculate,  exserted  awn,  the 
upper  bearing  a  short,  straight,  slender  awn  just  below  the  tip. 

Perennial,  rather  tall  grasses,  with-  flat  blades  and  rather  dense 
panicles.  Species  about  six,  in  the  temperate  regions  of  Eurasia; 
'  one  species  introduced  into  the  United  States. 

Type  species :  Arrhenatherum  avenaceum  Beauv. 

Arrhenatherum  Beauv.,  Ess.  Agrost.  55,  pi.  11,  f.  5.  1812.  Beauvois  figures 
one  species,  which  he  calls  Arrhenatherum  avenaceum.  This  is  Avena  elatior 
L.,  and  is  now  called  Arrhenatherum  elatius  (L.)  Mert.  and  Koch. 

Arrhenatherum  elatius  (PI.  XII;  fig.  59)  is  occasionally  cultivated 
in  the  humid  regions  of  the  United  States  as  a  meadow  grass  under 
the  name  of  tall  oat-grass.  It  is  a  fairly  satisfactory  forage  grass, 
but  the  seed  is  expensive  and  often  of  poor  quality.  This  species  is 
often  found  growing  spontaneously*  in  grassland  and  along  road- 
sides in  the  Northern  States. 

A  variety,  Arrhenatherum  elatius  bulb o sum  (Presl)  Koch,  has  ap- 
peared recently  in  some  of  the  Atlantic  States.  It  differs  from  the 
ordinary  form  in  having  at  the  base  of  the  stem  a  moniliform  string 
of  2  to  5  small  corms  5  to  10  mm.  in  diameter. 

1  See  Journ.  Hered,  5 :  56,  1914,  a  translation  of  an  article  by  Trabut.  Also  see  Norton, 
Amer.  Breed.  Assoc.  3:  281.  1907. 

97769°— 19— Bull.  772 8 


114  BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 


49.  AIRA  L. 
(Descliampsia  Beauv.) 

Spikelets  2-flowered,  disarticulating  above  the  glumes,  the  hairy 
rachilla  prolonged  behind  the  upper  floret  as  a  stipe,  this  sometimes 
bearing  a  reduced  floret;  glumes  about  equal,  acute 
or  acutish,  membranaceous ;  lemmas  thin,  truncate 
and  2  to  4  toothed  at  the  summit,  bearing  a  slender 
awn  from  or  below  the  middle,  the  awn  straight,  bent, 
or  twisted. 

Low  or  moderately  tall 
annual  or  usually  peren- 
nial grasses,  with  shining 
pale  or  purplish  spikelets 
in  narrow  or  open  pani- 
cles. Species  about  35,  in 
the  temperate   and   cool 
regions  of  both  hemispheres,  6  of  these 
being  in  the  United  States. 

Type  species :  Aira  caespitosa  L. 

Aira  L.,  Sp.  PI.  63,  1753 ;  Gen.  PI.,  eel.  5,  31. 
1754.  Fourteen  species  are  described.  The 
name  was  first  used  for  a  genus  by  Linnaeus 
in  his  Flora  Lapponica  in  1737,  where  he 
describes  four  species.  These  four  species 
are  named  in  the  Species  Plantarum :  7.  A. 
spicata,  8.  A.  caespitosa,  9.  A.  flexuosa,  10. 
A.  montana.  The  first  of  these,  A..spicata, 
is  referred  to  Trisetum ;  the  other  three  be- 
long to  Deschampsla,  as  recognized  in  most 
American  botanies.  The  genus  Aira,  as 
accepted  by  Bentham  and  Hooker  in  the 
Genera  Plantarum  and  by  Hackel  in  the 
Natiirlichen  Pflanzenfamilien,  is  based  upon 
the  last  two  of  the  original  Linnseari 


FIG.  59. — Tall  oat-grass,  Arrhenathcrum  elatius.     Plant,   X   i  ;  spikelet  and  fertile  floret, 

X  5. 


GENERA   OF    GRASSES   OF   THE    UNITED   STATES. 


115 


FIG.   60, — Tufted  hair-grass,  Aira  caespitosa.     Plant,    X    £  ;   spikelet  and  two   views   of 

floret,    X    5. 


116  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

species,  A.  praecox  and  A.  caryophyUca,  which  are  found  in  southern  Europe 
and  are  not  described  by  Linnaeus  in  his  Flora  Lapponica  nor  in  his  Flora 
Suecica.  Linnseus's  generic  idea  of  Aira  is  evidently  represented  by  the  four 
species  first  included  in  the  genus.  From  these  Aira  caespitosa  is  arbitrarily 
selected  as  the  type. 

Deschampsia  Beauv.,  Ess.  Agrost.  91,  pi.  18,  f.  3.  1812.  The  figured  species, 
the  type,  is  D.  caespitosa. 

Lerchenfeldia  Schur.,  Enum.  PI.  Transs.  753.  1866.  Three  species  are  in- 
cluded. Aira  flexuosa  L.,  on  which  L.  flexuosa  is  based,  is  taken  as  the  type. 

Aira  danthonioides  Trin.  of  the  Pacific  coast  is  an  annual.  Aira 
caespitosa  L.  (Deschampsia  caespitosa  Beauv.)  (fig.  60)  is  common 
in  moist  or  wet  soil  from  Newfoundland  to  Alaska  and  south  to  New 
Jersey,  Illinois,  and,  in  the  western  mountains,  to  New  Mexico  and 
southern  California.  It  is  a  tufted  perennial  1  to  4  feet  high,  with 
smooth,  narrow,  folded  blades  and  open  drooping  panicles,  4  to  12 
inches  long,  of  shining  pale-bronze  or  purplish  spikelets.  This  spe- 
cies, sometimes  called  tufted  hair-grass,  is  often  the  dominant  grass 
in  mountain  meadows,  where  it  furnishes  excellent  forage. 

50.  ASPEIS  Adans. 
(Aira  of  authors.) 

Spikelets  2-flowered,  the  rachilla  disarticulating  above  the  glumes, 
not  prolonged;  glumes  about  equal,  acute,  membranaceous  or  sub- 
scarious ;  lemmas  firm,  rounded  on  the  back,  tapering  into  two  slender 
teeth,  the  callus  with  a  very  short  tuft  of  hairs,  bearing  on  the  back 
below  the  middle  a  slender,  geniculate,  twisted,  usually  exserted  awn, 
this  reduced  or  wanting  in  the  lower  floret  in  one  species. 

Low,  delicate  annuals  with  small  open  or  contracted  panicles.  Spe- 
cies about  nine,  in  southern  Europe,  three  being  introduced  in  the 
United  States. 

Type  species :  Aira  praecor  L. 

Aspris  Adans.,  Fam.  PL  2:  496,  522.  1763.  The  references  cited  are  also 
cited  by  Linnseus  under  Aira  praecox. 

Caryophyllea  Opiz,  Seznam  27.    1852.    Based  on  Aira  caryophyllea. 

Fussia  Schur.,  Enum.  PI.  Transs.  754.  1866.  Three  species,  F.  praecox,  F. 
caryophyllea,  and  F.  capillaris,  are  included.  Aira  praecox,  upon  which  the 
first  species  is  based,  is  taken  as  the  type. 

Our  three  species  are  Aspris  caryopJiyllea  (L.)  Nash  (fig.  61),  A. 
praecox  (L.)  Nash,  and  A.  capillaris  (Host)  Hitchc.  ( Aira  capillaris 
Host) .  They  are  found  frequently  on  the  Pacific  coast  and  occasion- 
ally in  the  Eastern  States.  The  species  are  of  no  economic  importance. 


Weingaertneria  canescens  Bernh.  has  been  found  upon  ballast  at 
Philadelphia  and  on  Marthas  Vineyard.  This  is  a  low,  tufted  annual 
with  pale,  contracted  panicles,  differing  from  the  species  of  Aspris  in 
having  club-shaped  awns. 

51.  NOTHOLCUS  Nash. 
(Holcus  of  authors.) 

Spikelets  2-flowered.  the  pedicel  disarticulating  below  the  glumes, 
the  rachilla  curved  and  somewhat  elongate  below  the  first  floret,  not 
prolonged  above  the  second  floret;  glumes  about  equal,  longer  than 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES. 


117 


the  two  florets;  first  floret  perfect,  its  lemma  awnless;  second  floret 
staminate,  its  lemma  awned  on  the  back. 


FIG.  61. — Aspris  caryopliyllea.     Plant,   X   1 ;  spikelet  and  two  views  of  floret,   X   5. 

Perennial  grasses,  with  flat  blades  and  contracted  panicles.  Species 
about  eight,  Europe  and  Africa;  two  introduced  into  the  United 
States. 

Type  species :  Holcus  lanatus  L. 

Ginannia  Bubani,  Fl.  Pyren.  4:  321,  1901,  not  Scop.,  1777,  nor  Dietr.,  1804. 
P.ased  on  "  Holcus  L.  et  Auctor.,"  the  two  species  included,  G.  pubesccns  and  O. 
molli-x,  showing  that  it  is  to  the  species  congeneric  with  Holcus  lanatus  L.  that 
the  name  is  applied. 


118  BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 

Notholcus  Xash;  Hitch.,  in  Jepson,  Fl.  Calif.  3:  128.  1912.  Only  one  species 
described.  Notholcus  is  derived  from  the  Greek  nothos,  false,  and  Holcus,  the 
generic  name  formerly  applied  to  this  group.  Nash  1  spells  the  name  Nothoholcus. 
For  a  discussion  of  the  reasons  for  the  change  of  name,  see  page  266.  The  ge- 
neric name  Holcus  is  there  applied  to  the  sorghums,  necessitating  a  new  name 
for  the  velvet  grass. 

The  common  species  in  the  United  States  is  Notholcus  lanatus 
(L.)  Nash  (Holcus  lanatus  L.),  known  as  velvet  grass  (fig.  62). 
This  species  is  introduced  in  various  places  in  the  Eastern  States 
and  also  on  the  Pacific  coast,  where  it  is  abundant.  It  is  an  erect, 
grayish,  velvety-pubescent  grass  2  to  3  feet  tall,  with  a  contracted 
pale  or  purplish  panicle  2  to  4  inches  long.  Velvet  grass  is  some- 
times recommended  as  a  meadow  grass,  but  for  this  purpose  it  has 
little  value  except  on  moist  sandy  or  sterile  soil  where  other  grasses 
will  not  thrive.  It  has  been  used  with  some  success  in  sandy  fields 
around  the  mouth  of  the  Columbia  River  in  Washington  and  Oregon. 

A  second  species,  Notholcus  mollis  (L.)  Hitchc.,  with  creeping 
rhizomes,  has  been  introduced  in  California,  where  it  is  rare. 

52.  DANTHONIA  Lam.  and  DC. 

Spikelets  several-flowered,  the  rachilla  readily  disarticulating 
above  the  glumes  and  between  the  florets ;  glumes  about  equal,  broad 
and  papery,  acute,  mostly  exceeding  the  uppermost  floret;  lemmas 
rounded  on  the  back,  obscurely  several-nerved,  the  base  with  a  strong 
callus,  the  apex  bifid,  the  lobes  acute,  usually  extending  into  slender 
awns,  a  stout  awn  arising  from  between  the  lobes ;  awn  flat,  tightly 
twisted  below,  geniculate,  exserted,  including  three  nerves  of  the 
lemma. 

Tufted,  low  or  moderately  tall  perennials,  with  few-flowered,  open, 
or  spikelike  panicles  of  rather  large  spikelets.  Species  about  100,  in 
the  temperate  regions  of  both  hemispheres;  especially  abundant  in 
South  Africa ;  12  species  in  the  United  States,  about  equally  divided 
between  the  Eastern  and  the  Western  States. 

Type  species :  Avena  spicata  L. 

Danthonia  Lam.  and  DC.,  Fl.  Franc.  3:  32.  1805.  The  work  cited  is  a  local 
flora  in  which  the  two  French  species  are  described,  D.  decumbent  (which  is 
the  same  as  Xicfillnyia  (lecuiubcnx)  and  D.  prorincialis.  The  authors,  however, 
mention  in  the  paragraph  preceding  the  one  devoted  to  the  generic  description 
that  "besides  the  species  described  below  one  ought  to  refer  to  this  genus,  1st, 
Avena  spicata  L.  or  Avena  ylumosa  Michx. ;  2d,  Arena  cfilicina  Lam.  not  Vill." 
Of  the  four  species  mentioned,  three  are  congeneric  with  Avena  spicata  and 
correspond  with  the  generic  description  better  than  does  Danthonia  decumbens, 
which  is  the  first  species  described  under  Danthonia.  Avena  spicata  is  se- 
lected as  the  type  of  Dauthonia.2  Piper3  has  selected  Festuca  decumbens  L. 
(Danthonia  decumbens)  as  the  type  of  Danthonia  because  it  is  the  first  species 
described  under  Danthonia,  and  takes  up  Merathrepta  Raf.  for  the  species 
generally  referred  to  Danthonia.  Nelson  and  Macbride 4  take  up  Pentameris 
Beauv.  in  place  of  Merathrepta. 

iBritt.  and  Brown,  Illustr.  Fl.,  ed.  2.  1:  214.     1913. 
2  See  Hitchc.,  Bot.  Gaz.  57 :  328.     1914. 
sContr.  TT.  S.  Xat.  Herb.  11:  122.     1906. 
*Bot.  Gaz.  56:  469.      1913. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


119 


PIG.  62. — Velvet  grass,  Xotliolcns  la  nut  us.     Plant,    X    l;   spikelet,  florets  with  glumes 
removed,  arid  mature  fertile  floret,  all  X  5. 


120  BULLETIN   772,   U.   S.   DEPARTMENT  OF   AGRICULTURE. 


Pentameris  Beauv.,  Ess.  Agrost.  92,  pi.  18,  f.  8.    1812.    P.  tlmarii  is  the  type, 
as  this  is  the  single  species  mentioned  and  figured.     This  is  a  South  African 

species  and  represents  a  group  in 
which  the  lateral  teeth  of  the  lemmas 
are  2-awned.  The  group  is  considered 
to  be  generically  distinct  from  Dan- 
thonia  by  Stapf.1  The  name  is  taken 
up  by  Nelson  and  Macbride  in  place  of 
Merathrepta  Raf.2 

Merathrepta  Rat,  Bull.  Bot.  Seringe 
1:  221.  1830.  The  genus  is  described 
briefly  and  Arena  spicata  mentioned. 
This  species  is,  therefore,  the  type. 

One  species  of  Danthqnia,  D. 

spicata  (L.)  Beauv.  (fig.  63),  is 
common  on  sterile  hills  and  in 
dry,  open  woods  in  the  Eastern 
States,  where  it  is  sometimes 
called  poverty  grass.  It  can  be 
recognized,  even  when  not  in 
flower,  by  its  small  tufts  of  curly 
leaves.  In  the  Western  States 
the  species  are  found  in  grass- 
land and  contribute  somewhat 
toward  the  forage  value  of  the 
range,  but  usually  they  are  not 
abundant.  All  our  species  pro- 
duce cleistogenes  (enlarged  fer- 
tile cleistogamous  spikelets)  in 
the  lower  sheaths,3  and  the  culms 
finally  disarticulate  at  the  nodes 
below  these. 


FIG.  G3. — Wild  oat-grass,  Danthonia  spicata.     Plant,   X   I  ',  spikelet,  floret,  and  a  cleisfo- 
gene  from  the  axil  of  a  lower  leaf,  all   X   5. 

1  Thiselt.   Dyer,  Fl.  Cap.   7 :  512.     1898. 

2  See   following  paragraph   on   Merathrepta. 

3  Chase,  Amer.  Journ.  Bot.  5:254.      1918. 


GENERA  OF  GRASSES   OF  THE  UNITED  STATES.  121 

5.  AGROSTIDEAE,  THE  TIMOTHY  TRIBE. 

53.  CALAMAGROSTIS  Adans. 

Spikelets  1-flowered,  the  rachilla  disarticulating  above  the  glumes, 
usually  prolonged  behind  the  palea  as  a  short,  commonly  hairy  bristle ; 
glumes  about  equal,  acute  or  acuminate;  lemma  shorter  and  usually 
more  delicate  than  the  glumes,  the  callus  bearing  a  tuft  of  hairs, 
which  are  often  copious  and  as  long  as  the  lemma,  awned  from  the 
back,  usually  below  the  middle,  the  awn  being  delicate  and  straight, 
or  stouter  and  exserted,  bent  and  sometimes  twisted;  palea  shorter 
than  the  lemma. 

Perennial,  usually  moderately  tall  or  robust  grasses,  with  small 
spikelets  in  open  or  usually  narrow,  sometimes  spikelike  panicles. 
Species  over  100,  in  the  cool  and  temperate  regions  of  both  hemi- 
spheres ;  26  species  in  the  United  States,  mostly  in  the  western  moun- 
tains. 

Type  species:  Arundo  calamagrostix  L. 

Calamagrostis  Adans.,  Fam.  PI.  2:  31,  530.  1763.  Adanson  describes  no 
species  but  in  the  index  there  is  given  under  Kalamagrostis  Diosk.,  three  names 
or  citiations,  Negil.  Arab.,  Gramen.  Sheuz.  t.  3.  f.  5.,  and  Arundo  Lin.  The 
reference  to  Scheuchzer  is  found  in  Linnseus's  Species  Plantarum  under  Arundo 
calamagrostis  (1:  82),  which  consequently  is  the  type  of  Calamagrostis. 

Deyeuxia  Clarion;  Beauv.,  Ess.  Agrost.  43,  pi.  9,  f.  9,  10.  1812.  Type,  D. 
montana,  the  first  of  the  two  species  figured. 

Amagris  Raf.,  Princip.  Fondarnent.  Somiologie  27.  1814.  A  new  name  pro- 
posed for  Calamagrostis,  because  that  is  formed  of  two  other  names. 

Athernotus  Dulac,  Fl.  Hautes  Pyr.  74.  1867.  Based  on  "  Calamagrostis  Ad." 
Lunell *  uses  this  name  for  Calamovilfa,  but  Dulac  bases  the  genus  on  Cala- 
magrostis Adans.,  and  the  three  species  he  includes  belong  in  Calamagrostis, 
not  in  Calamovilfa. 

By  some  authors  the  species  with  prolonged  rachilla  are  segregated 
as  a  distinct  genus,  Deyeuxia,  the  name  Calamagrostis  being  retained 
for  those  species  in  which  the  rachilla  is  not  prolonged.  The  Ameri- 
can species  all  belong  to  the  section  Deyeuxia. 

Four  Pacific  coast  species  have  loose,  open  panicles.  In  all  the 
other  species  the  panicle  is  rather  compact,  in  some  cases  spikelike. 
The  commonest  species  in  the  United  States  is  CaZaanagrostis  cana- 
densis  (Michx.)  Beauv.  (fig.  64),  growing  in  swamps  and  low  ground 
from  New  England  to  Oregon,  and  southward  in  the  mountains  and 
northward  to  the  arctic  circle.  It  is  an  important  source  of  wild  hay 
from  Wisconsin  to  North  Dakota,  but  is  of  only  medium  value  for 
grazing.  Much  of  the  marsh  hay  of  Wisconsin  and  Minnesota  be- 
longs to  this  species,  which  in  that  region  is  called  blue  joint.  This  is 
the  dominant  grass  in  the  interior  of  Alaska.  The  species  is  distin- 
guished by  having  flat  blades,  a  somewhat  lax,  usually  nodding 
panicle,  the  hairs  at  the  base  of  the  floret  copious  and  as  long  as  the 
lemma,  the  awn  straight,  delicate,  not  exserted  beyond  the  glumes,  the 
latter  3  to  5  mm.  long. 

i  Amor.  Midi.  Nat.  4:  218.     1915. 


122  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.   G4. — Bluojoint,   Cala-mauruatis  canadcnais-      Plant,    X    \  ;  spikelet  and  floret,    X    5. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  123 

C alamagrostis  scabra  Presl,  closely  allied  to  the  above,  but  with 
somewhat  larger  spikelets,  is  abundant  along  the  coast  from  Oregon 
to  Alaska.  This  has  been  incorrectly  referred  to  C.  langsdorfii 
(Trin.)  Link,  of  Siberia.  In  general,  the  species  of  Calamagrostis 
are  important  forage  grasses.  Pine-grass  (C.  rubescens  Buckl.)  is 
common  in  the  mountains  of  Oregon  and  Washington,  where  it  forms 
an  important  part  of  the  forage. 

For  a  revision  of  the  species  of  Calamagrostis  found  in  the  United 
States,  see  Kearney,  U.  S.  Dept.  Agr.,  Div.  Agrost.  Bull.  11.  1898. 

54.  AMMOPHILA  Host. 

Spikelets  1 -flowered,  compressed,  the  rachilla  disarticulating  above 
the  glumes,  produced  beyond  the  palea  as  a  short  bristle,  hairy  above; 
glumes  about  equal,  chartaceous ;  lemma  similar  to  and  a  little  shorter 
than  the  glumes,  the  callus  bearing  a  tuft  of  short  hairs ;  palea  nearly 
as  long  as  the  lemma. 

A  tough,  rather  coarse,  erect  perennial,  with  hard,  scaly,  creeping 
rhizomes,  long,  tough,  involute  blades,  and  a  pale,  dense,  spikelike 
panicle.  One  species  is  found  on  the  sandy  seacoast  of  Europe  and 
northern  .North  America  as  far  south  as  North  Carolina  and  on  the 
shores  of  the  Great  Lakes,  a  second  species  around  the  Baltic. 

Type  species:  Arundo  arenaria  L. 

Ammophila  Host,  Gram.  Austr.  4:  24,  pi.  41.  1809.  Only  one  species  de- 
scribed. A.  anmdinacea  Host,  based  on  Arundo  arenaria  L. 

Psamma  Beaiiv.,  Ess.  Agrost.  143,  pi.  6,  f.  1.  1812.  The  one  species,  P. 
Uttoralis,  is  Ammophila  arenaria. 

AmmopMla  arenaria  (L.)  Link  (fig.  65)  is  an  important  sand- 
binding  grass  in  Europe,  being  used  there  to  hold  the  barrier 
dunes  along  the  coast.  In  this  country  it  has  been  tried  with  success 
on  Cape  Cod  and  at  Golden  Gate  Park,  San  Francisco.1  It  is  called 
beach-grass  and  less  frequently  marram  grass  and  sea  marram. 

55.  CALAMOVILFA  Hack. 

Spikelets  1-flowered,  the  rachilla  disarticulating  above  the  glumes, 
not  prolonged  behind  the  palea ;  glumes  unequal,  acute,  chartaceous ; 
lemma  a  little  longer  than  the  second  glume,  chartaceous,  awnless, 
glabrous  or  pubescent,  the  callus  bearded ;  palea  about  as  long  as  the 
lemma. 

Perennial,  rigid,  usually  tall  grasses,  with  narrow  or  open  panicles, 
some  species  with  creeping  rhizomes.  Species  four,  confined  to  the 
United  States  and  southern  Canada. 

Type  species  :  Calam.agrostis  brevipilis  Gray. 

Calamovilfa  Hack.,  True  Grasses  113.  1890.  The  True  Grasses  is  a  transla- 
tion by  Scribner  and  Southworth  of  the  article  on  grasses  in  Engler  and  Prantl's 
Natiirliclien  Pflanzenfamilien.  Scribner  has  added  bracketed  notes.  In  a  para- 

1  For  a  full  discussion,  see  Hitchcock,  U.  S.  Dept.  Agr.,  Bur.  PI.  Ind.  Bull.  57  ;  Westgate, 
U.  S.  Dept.  Agr.,  Bur.  PI.  Ind.  Bull.  05.  1904. 


124          BULLETIN  772,  U.   S.  DEPARTMENT  OF  AGRICULTURE. 


FIG.  65. — Beach-grass,  AmmopJiila  arenaria.     Plant,    X    J  ;  spikelet  and  floret,    X    5. 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES.  125 

graph  quoted  from  Hackel  ("Hackel  in  MS.")  is  a  statement  that  two  species, 
Calamagrostis  brevipilis  Gray  and  C.  longifolia  Hook.,  may  best  be  considered  a 
separate  g3iius,  Calamovilfa.  Scribner  adds  a  note  formally  describing  the  genus 
Calamovilfa  and  mentions  the  two  species,  Calamovilfa  brevipilis  and  C.  longi- 
folia.  The  first  is  selected  as  the  type. 

The  genus  differs  from  Calamagrostis  in  the  chartaceous  lemma, 
from  our  species  of  Calamagrostis  in  the  absence  of  a  prolonged  ra- 
chilla,  and  from  Ammophila  in  the  more  open  panicles  and  in  the 
absence  of  the  prolongation  of  the  rachilla. 

The  four  species  are  Calamovilfa  brevipilis  (Torr.)  Scribn.,  in  the 
pine  barrens  from  New  Jersey  to  North  Carolina;  C.  curtissii 
(Vasey)  Scribn.,  confined  to  Florida;  C.  longifolia  (Hook.)  Scribn. 
(fig.  66),  of  the  Great  Plains  and  the  dune  region  of  Lake 
Michigan;  C.  gigantea  (Nutt.)  Scribn.  and  Merr.,  also  of  the 
Great  Plains.  The  first  two  species  are  without  creeping  rhizomes; 
the  other  two  have  numerous  stout  rhizomes  and  are  excellent  sand 
binders.  Calamovilfa  longifolia  and  C.  gigantea  are  closely  re- 
lated. They  are  differentiated  by  the  less  expanded  panicle  and 
glabrous  florets  of  the  first  and  the  spreading  panicle,  larger  spike- 
lets,  and  villous  florets  of  the  second. 

Calamovilfa  longifolia,  the  commonest  species,  is  of  some  value  for 
forage,  but  is  rather  coarse  and  woody. 

56.  AGBOSTIS  L.,  the  bent-grasses. 

Spikelets  1-flowerecl,  disarticulating  above  the  glumes,  the  rachilla 
usually  not  prolonged;  glumes  equal  or  nearly  so,  acute,  acuminate, 
or  sometimes  awn-pointed,  carinate,  usually  scabrous  on  the  keel  and 
sometimes  on  the  back;  lemma  obtuse,  usually  shorter  and  thinner  in 
texture  than  the  glumes,  awnless  or  dorsally  awned,  often  hairy  on 
the  callus;  palea  usually  shorter  than  the  lemma,  2-nerved  in  only 
a  few  species,  usually  small  and  nerveless  or  obsolete. 

Annual  or  usually  perennial,  delicate  or  moderately  tall  grasses, 
with  glabrous  culms,  flat  or  sometimes  involute,  scabrous  blades,  and 
open  or  contracted  panicles  of  small  spikelets.  Species  about  100, 
in  the  temperate  and  cold  regions  of  the  world,  especially  in  the 
Northern  Hemisphere.  About  25  species  are  found  in  the  United 
States,  some  of  these  being  found  also  in  Europe. 

Type  species :  Agrostis  stolonifera  L. 

Agrostis  L.,  Sp.  PI.  61,  1753;  Gen.  PI.,  ed.  5,  30.  1754.  Linnaeus  describes 
12  species,  dividing  them  into  two  groups,  Aristatae  and  Muticae.  The  descrip- 
tion of  the  genus  refers  to  the  lemma  as  being  awned  and  to  the  presence  of 
a  palea  ("Cor.  bivalvis  .  .  .  altera  majore  aristata").  If  the  type  species 
must  agree  with  the  description  in  the  fifth  edition  of  the  Genera  Plan- 
tarum,1  it  must  be  chosen  from  the  first  group,  Aristatae,  and  from  those 

1  See  American  Code  of  Botanical  Nomenclature,  Bull.  Torrey  Club  84 :  174.  1907.  The 
statement  is  made  that  "the  genera  of  Linnseus's  Species  riantarum  (1753)  are  to  be 
typified  through  the  citations  given  in  his  Genera  Plantarum  (1754)."  There  is  no 
citation  given  for  Agrostis  and  the  code  docs  not  definitely  require  that  the  genera  must 
be  interpreted  by  the  descriptions  here  given ;  hence  the  type  species  may  be  chosen  inde- 
pendent of  this  description. 


126  BULLETIN    772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


FIG.    GG.—Calamovilfa   longifolia.      Plant,    X    \  ;   spikelet  and   floret,    X    5. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  127 

species  possessing  a  palea.  Prom  this  standpoint  the  type  species  would  be 
Agrostis  spica-venti,  which  is  referred  by  many  botanists  to  Apera  but 
which  is  here  included  in  Agrostis.  However,  the  description  of  Agrostis  in 
the  fifth  edition  was  not  written  by  Linnauis  for  that  edition.  It  was  copied 
f:*om  the  first  edition,  published  in  1737,  at  which  time  LinnaBUs's  concept  of 
Agrostis  was  chiefly  based  on  Stipa  calamagrostis.  By  the  time  the  Species 
Plantarum  was  prepared  his  concept  of  the  genus  Agrostis  had  changed,  but  he 
did  not  make  the  corresponding  change  in  the  description  in  the  fifth  edition 
of  the  Genera  Plantarum  which  he  prepared  at  the  same  time.  It  seems  best, 
then,  to  ignore  this  description  and  select  the  type  species  from  the  economic 
species.  Therefore  A.  stolonifera *  has  been  selected  as  the  type  species  of 
Agrostis.  Several  of  the  original  species  are  now  referred  to  other  genera: 
.1.  miliacea  and  A.  paradoxa  to  Oryzopsis;  A.  arundinacea  to  Oalamagrostis ; 
A.  minima  to  Mibora ;  A.  virginica  and  A.  indica  to  Sporobolus. 

Vilfa  Adans.,  Fam.  PI.  2:  495.  1763.  Adanson  cites  "  Gramen  canin.  supin. 
C.  B.  Theat.  12  "  arid  in  the  index,  "  Gramen  canin.  supin.  minus  C.  B."  Lin- 
naeus 2  gives  under  Agrostis  stolonifera  the  citation,  "  Gramen  cariinum  supinum 
minus  Scheuch.  gram.  128."  Scheuchzer 8  credits  the  citation  to  C.  Bauhin. 
Therefore  Agrostis  stolonifera  L.  is  the  type  of  Vilfa  Adans. 

Apera  Adans..  Fam.  PI.  2:  495.  1763.  Adanson  refers  directly  to  "Agrostis  1. 
Lin.  Sp.  61."  The  first  species  of  Agrostis  described  by  Linnaeus  in  his  Species 
Plantarum  (p.  61)  is  A.  spica-venti,  which  becomes  the  type  of  Apera. 

Trichodium  Michx.,  Fl.  Bor.  Amer.  1:  41,  pi.  8.  1803.  Two  species  are  de- 
scribed, T.  laxiflorum  and  T.  decumbens.  The  first  species,  iliustiated  in  plate 
8,  is  the  type.  This  is  the  same  as  Afrostis  hiemalis.  Trichodium  decumbens 
is  the  same  as  A.  perennans.  Michaux  distinguished  the  genus  from  Agrostis 
by  the  absence  of  the  palea. 

Agraulus  Beauv.,  Ess.  Agrost.  5,  pi.  4,  f.  7.  1812.  Two  species,  based  on 
Afjrostis  canina  L.  and  A.  alpina  Willd.,  are  included,  the  first  being  figured  and 
therefore  the  type. 

Anemagrostis  Trin.,  Fund.  Agrost.  128.  1820.  Two  species,  based  on  Agrostis 
spica-venti  L.  and  A.  interrupta  L.,  are  included,  the  first  of  which  is  taken  as 
the  type. 

Notonema  Raf.,  Neogenyt.  4.  1825.  A  single  s-pecies  is  included,  Agrostis 
arachnoides  Ell.  (A.  elliottiana  Schult.) 

Podagrostis  Scribn.  and  Merr.,  Contr.  U.  S.  Nat.  Herb.  13 :  58.  1910.  Based 
upon  Agrostis,  section  Podagrostis  Griseb.  in  Ledeb.  Fl.  Ross.  4:  436.  1853. 
A  single  species,  Agrostis  aequivalvis  Trin.,  referred  here  in  each  case.  A.  thur- 
beriana  Hitchc.  also  belongs  to  this  group,  which  forms  a  section  of  Agrostis. 

In  Agrostis  spica-venti,  A.  aequivalvis,.  and  A.  thurberlana  the 
rachilla  is  prolonged  behind  the  palea  as  a  minute  bristle  or  stipe, 
and  the  lemma  and  palea  are  nearly  equal  and  about  as  long  as  the 
glumes.  The  palea  is  obsolete  in  many  species  (which  have  been 
separated  by  some  authors  under  the  generic  name  of  Trichodium), 
and  is  much  shorter  than  the  lemma  in  several  other  species.  The 
awn,  when  present,  may  arise  from  the  back  of  the  lemma  just  above1 

1  See  Hitchcock,  Bot.  Gaz.  38:141.  1904.  On  the  basis  of  the  specimen  in  the  Lin- 
naean  Herbarium  and  of  the  synonymy,  the  name  A.  stolonifera  was  there  applied  to  the 
species  called  A.  vertictllata  Vill.  But  on  reconsideration  it  seems  best  to  accept  the 
name  cis  applied  by  Swedish  botanists.  Linnaeus  was  most  familiar  with  the  Swedish 
grass,  and  cites  as  the  first  synonym  under  A.  stolonifera  the  phrase  name  he  had  applied 
to  it  in  his  Flora  Suecica.  He  confused  with  this  the  South  European  species,  A.  ver- 
ticillata,  a  specimen  of  which  in  his  herbarium  he  marked  "  A.  stolonifcra/'  but  we  may 
assume  that  he  intended  to  apply  the  name  A.  stolonifera  to  the  grass  from  Sweden.  In 
the  latter  work  Linnaeus  states  that  the  plant  is  known  popularly  as  Kryp-hwen.  Dr. 
Carl  Lindman,  who  has  kindly  sent  a  series  of  specimens  of  the  species  in  question,  states 
in  a  letter  that  the  grass  in  Sweden  called  Krypven  (the  modern  spelling)  is  the  species 
described  by  Swedish  botanists  as  A.  stolonifera.  This  has  a  long  ligule,  an  open  panicle, 
and  an  erect  culm  decumbent  at  base  or  producing  stolons. 

2Sp.    PI.    62.      1753.  3  Agrost.    128.      1719. 


128  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


the  base  (A.  howellli  Scribn.)  or  from  about  the  middle  (A.  exarata 
microphylla  (Steud.)  Hitchc.)  or  from  just  below  the  apex  (A.  spica- 

venti,  A.  ellio ttiana) . 
The  hairs  on  the  callus 
are  usually  minute,  but 
are  half  as  long  as  the 
lemma  in  A.  hallii  Vasey. 
Three  of  our  species  are 
annuals,  A.  spica-venti 
L.,  introduced  from 
Europe;  A.  exigua 
Thurb.,  of  California; 
and  A.  ellio  ttiana  Schult., 
of  the  Southern  States. 
The  genus  furnishes 
several  species  that  are 
important  forage  plants 
either  under  cultivation 
or  in  the  mountain  mead- 
ows of  the  Western  States. 
The  most  important  is 
Agrostis  palustris  Huds. 
(A.  alba  of  authors1) 
(PI.  XIII;  fig.  67), 
known  usually  as  redtop 
because  of  the  reddish 


1  The  name  Agrostis  alba  L. 
(Sp.  PI.  G3.  1753)  is  of  doubtful 
application.  In  the  original 
publication  the  name  is  founded 
solely  on  the  citation  "  Roy. 
lugdb.  59  "  (Royen,  Flora  Ley- 
densis).  Royen's  citation  of 
synonym  refers  to  Poa  (appar- 
ently P.  nemoralis).  There  are 
several  sheets  in  Linnaeus's 
herbarium,  one  of  which  bears 
the  name,  Agrostis  alba,  in 
Linnseus's  script.  These  speci- 
mens are  the  Agrostis  alba  as 
generally  understood,  but, 


FIG-  07. — Redtop,  Agrostis  falustris.     Plant,    X    «  ;  spikelet,  open  and  closed,  and  floret, 

X    5. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XIII. 


REDTOP  (AGROSTIS  PALUSTRIS). 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XIV. 


TIMOTHY  (PHLEUM  PRATENSE). 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  129 

color  of  the  panicle.  This  species  is  an  erect  plant  2  to  4  feet 
high,  producing  rhizomes,  and  often  decumbent  at  base,  with  flat 
blades,  prominent,  somewhat  pointed  ligule,  and  an  opeia,  usually  red- 
dish panicle,  2  to  12  inches  long,  contracted  in  fruit,  the  branches  in 
whorls.  Redtop  is  cultivated  as  a  meadow  and  pasture  grass  in  the 
Northern  States,  especially  upon  soils  lacking  in  lime  and  upon  soils 
too  wet  for  timothy.  In  Pennsylvania  and  some  other  localities  this 
species  is  called  herd's-grass. 

Agrostis  capillaris  L.  (A.  tennis  Sibth.,  A.  vulgaris  With.,  A. 
alba  vulgaris  Thurb.),  Rhode  Island  bent,1  differs  from  red- 
top  in  its  smaller  size,  more  delicate  culms  and  foliage,  short  truncate 
ligule,  smaller,  more  open,  and  fewer  flowered  panicle,  not  contract- 
ing after  flowering.  Stolons  are  usually  absent  but  may  be  as  much 
as  4  to  8  inches  long.  Rhode  Island  bent  is  often  used  as  a  lawn 
grass,  especially  in  the  Northeastern  States,  where  the  soil  is  lacking 
in  lime  and  bluegrass  does  not  thrive.  In  some  botanical  works  the 
name  Agrostis  canina  has  been  incorrectly  applied  to  Rhode  Island 
bent.  Agrostis  canina  L.,  a  European  species  occasionally  introduced 
into  the  Eastern  States,  is  a  frequent  constituent  of  the  commercial 
seed  of  creeping  bent.  It  is  called  velvet  bent  and  gives  promise 
of  being  a  fine  lawn  grass. 

Carpet  bent,  also  called  creeping  bent,  is  a  form  of  A.  stolonifera. 
This  produces  stolons  from  1  to  4  feet  long  and  is  also  used  as  a 
lawn  grass  in  the  same  region  as  that  described  for  Rhode  Island  bent. 
The  seed  has  been  imported  from  southern  Germany. 

Fiorin  is  a  name  that  was  applied  in  England  to  a  coast  form  with 
stoloniferous  habit,  long  ligule,  and  narrow  dense  panicles.  This 
form  is  found  along  the  northern  Atlantic  coast  of  Europe  and 
America  and  along  the  Pacific  coast  from  British  Columbia  to  north- 
ern California.  It  has  been  called  A.  maritima  Lam.  and  A.  alba 
mcuritima  (Lam.)  Meyer.  It  is  apparently  indigenous  in  America, 
while  A.  capillaris  and  A.  palmtris  appear  to  be  introductions. 

Several  native  species  of  Agrostis  are  found  in  the  western  part  of 
the  United  States,  especially  in  mountain  meadows.  One  of  the 
commonest  of  the  western  species  is  A.  exarata  Trin.,  with  contracted, 
sometimes  spikelike,  panicles  and  awned  or  awnless  spikelets,  found 
at  all  altitudes  throughout  the  western  portion  of  the  United  States. 

according  to  Jackson  (Index  to  the  Linnsean  Herbarium,  Proc.  Linn.  Soc.  London, 
124th  Sess.  Suppl.  1912),  these  specimens  were  added  to  the  herbarium  after  1753  and 
can  not,  therefore,  have  weight  in  determining  the  original  application  of  the  name.  Lin- 
naeus did  not  refer,  under  Agrostis  alba,  to  his  flora  of  Sweden.  It  would  appear  that  he 
did  not  intend  to  apply  the  name  originally  to  a  Swedish  plant.  The  species  usually 
known  as  Agrostis  alba-  is  common  in  Sweden,  but  apparently  was  included  by  Linnaeus 
under  A.  stolonifera,  to  which  it  is  closely  allied.  It  was  not  until  later  that  he  applied 
the  name  to  the  species  as  now  represented  in  his  herbarium.  Under  these  circumstances 
it  seems  best  to  drop  the  name  Agrostis  alba,  as  has  been  done  by  Piper  (U.  S.  Dept.  Agr. 
Bull.  692,  1918)  and  by  Stapf,  as  indicated  in  a  letter  to  Piper. 

1  See  Piper,  The  Agricultural  Species  of  Bent  Grasses.    U.  S.  Dept.  Agr.  Bull.  692.   1918 

97709°— 19— Bull.  772 9 


130  BULLETIN   772,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 


This  is  an  important  range  grass.  Common  on  the  Pacific  slope  is 
A.  diegoensis  Vasey,  with  creeping  rhizomes,  spreading  panicles,  and 
often  awned  spikelets. 


Two  native  species  belonging 
to  the  group  in  which  the  palea 
is  lacking  are  common  in  -the 
eastern  United  States.  Agrostis 
perennam  (Walt.)  Tuckerm.  is 
a  woodland  species  with  open 
panicle.  Agrostis  hiemalis 
(Walt.)  B.  S.  P.  (fig.  68)  is  a 
delicate  open-ground  species 
with  very  diffuse  capillary  pani- 
cle, which  at  maturity  breaks 
away  from  the  plant  as  a  tumble- 
weed.  This  species,  called  hair- 
grass  and  tickle  grass,  is  found 
throughout  the  United  States. 

Agrostis  spica-venti  L.  (fig. 
69),  a  European  species,  sparingly  introduced  in  the  Eastern  States, 
has  been  made  the  type  of  a  distinct  genus,  Apera,  being  distinguished 
by  the  prolongation  of  the  rachilla  and  the  long  delicate  awn  from 


FIG.  68. — Tickle  grass,  Agrostis 
hiemalis.  Plant,  X  \  ',  spikelet 
and  floret,  X  5. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


331 


FIG.  69. — Agrostis  spica-venti.     Plant,    X    I ;  g^mes  and  floret,    X    5. 


132  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

just  below  the  apex  of  the  lemma.  These  characters  are  not  deemed 
sufficient  to  separate  it  from  our  species.  The  rachilla  is  prolonged 
in  A.  aequivalvis  and  a  similar  awn  is  found  in  the  annual  A.  elliot- 
tiana  Schult. 

For  a  revision  of  the  species  of  Agrostis  found  in  the  United  States, 
see  Hitchcock,  U.  S.  Dept.  Agr.,  Bur.  PL  Ind.  Bull.  68.     1905. 

57.  PHIPPSIA   (Trin.)    11.  Br.' 

Spikelets  1-flowered,  disarticulating  above  the  glumes,  the  rachilla 
not  prolonged;  glumes  unequal,  minute,  the  first  sometimes  wanting; 

lemma  thin,  somewhat 
keeled,  3-nerved,  acute; 
pa  lea  a  little  shorter 
than  the  lemma,  dentate. 
A  dwarf,  tufted  per- 
ennial, with  n  a  r  r  o  w, 
few  -  flowered  panicles 
of  small  spikelets.  Spe- 
cies one,  in  the  arctic 
regions  of  both  hemi- 
spheres; also  on  the  al- 
pine summits  of  Colo- 
rado. 


FIG.  70. — Phippsia  algida.  Plant,  X  £  ;  spikelet  and 
branchlet  of  inflorescence  with  the  glumes  of  lower 
spikelets  remaining,  and  floret,  all  X  5. 


Type     species :     Agrostis 

Soland. 

( N»lpo<f,inin  s  11  b,ge  n  u  s 
Phippsia  Trin.,  in  Spreng. 
Neu.  Entd.  2:  37.  1821. 

Phippsia  R.  Br.,  Suppl.  App.  Parry's  Voy.  184.  1824.  A  single  species  de- 
scribed, P.  algida,  based  on  Ayrostitt  algida  Soland. 

Phippsia  algida  (Soland.)  R.  Br.  (fig.  TO) 'is  known  in  the  United 
States  only  from  a  few  localities  in  the  alpine  regions  of  Colorado. 
It  was  first  described  as  Agrostis  algida  by  Solander.1 

58.  COLEANTHUS  Seidel. 

Spikelets  1-flowered;  glumes  wanting;  lemma  ovate,  hyaline, 
terminating  in  a  short  awn ;  palea  broad,  2-keeled. 

A  dwarf  annual,  about  an  inch  high,  with  short  flat  blades  and 
small  few-flowered  panicles.  Species  one,  northern  Eurasia,  intro- 
duced in  America. 

Type  species:  Schmidtia  subtilis  Tratt. 

Schmidtia  Tratt.,  Fl.  Oesterr.  Kaiserth.  1:  12,  pi.  10,  1816,  not  Schmidtia 
Moench,  1802.  Only  one  species  described. 

Coleanthus  Seidel;  Roem.  and  Schult.,  Syst.  Veg.  2:  276.  1817.  Only  one 
species  described,  C.  xubtilis,  based  on  &clinii<Iti<t  xubtilix. 


i  In  Tliipps  Voy.  200.     1810, 


GENERA  OF  GRASSES   OF  THE  UNITED  STATES.  133 

Coleanthus  xuhtiUx  (Tnitl.)  Seidel  (fig.  71),  introduced  from 
Europe,  grows  on  mud  flats  along  the  Columbia  River,  where  it  was 
collected  by  Howell  (on  Sauvies  Island,  Oreg.)  and  by  Suksdorf 
(western  Klickitat  County,  Wash.). 


Mibora  minima  (L.)  Desv.  has  been  found  at  Plymouth,  Mass. 
This,  the  only  species  of  the  genus,  is  a  low  annual,  differing  from 
Coleanthus  and  Phippsia  in  having  glumes  longer  than  the  lemma, 
the  very  small  spikelets  in  simple  spikes.  Introduced  from  Europe. 


59.  CINNA  L. 


Spikelets  1 -flowered,  disarticulting  below  the  glumes,  the  rachilla 
forming  a  stipe  below  the  floret  and  produced  behind  the  palea  as  a 
minute  bristle;  glumes  equal,  1-nerved;  lemrria  similar  to  the  glumes, 


FIG.  71. — Coleanthus  nubtilis.     Plant,   X   1 ;  lemma  and  palea  and  two  views  of  spikelet 

with  ripe  caryopsis,    X   20. 

nearly  as  long,  3-nerved,  bearing  a  minute,  short,  straight  awn  just 
below  the  apex ;  palea  apparently  1-nerved,  1-keeled. 

Tall  perennial  grasses,  with  flat  blades  and  paniculate  inflorescence. 
Species  three,  North  America  and  northern  Eurasia,  two  in  the 
United  States  and  one  in  Mexico  and  southward. 

Type  species:  Cinna  arundinacea  L. 

Cinna  L.,  Sp.  PI.  5,  1753;  Gen.  PI.,  ed.  5,  6.  1754.  A  single  species  is 
described. 

Abobi  Arlans.,  Fam.  PI.  2:  31,  511.  1763.     Based  on  "Cinna  Lin." 

Cinnastrum  Fourn.,  Mex.  PL  2:  90.  1886.  Two  species  are  given,  C.  miliaceum 
and  ('.  ])<>u<' forme,  both  referable  to  Ginna  poaeformis  (H.  B.  K.)  Scribn.  and 
Merr. 

The  prolongation  of  the  rachilla  is  less  than  0.5  mm.  in  our 
species,  but  in  Cinna  poaeformis  of  Mexico  it  is  half  as  long  as  the 
palea.  The  palea  is  1-nerved  in  C.  arundinacea.  In  C.  poaeformis 
the  2  nerves  are  close  together  but  distinct.  In  C .  latifolia  the  palea 
is  apparently  1-nerved,  but  the  2  nerves  separated  when  the  palea  is 
split  along  the  keel. 


134          BULLETIN  772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

Cinna  arundinacea  (fig.  72),  with  somewhat  contracted  panicle  and 
spikelets  5  mm.  long,  grows  in  moist,  usually  shaded  places  in  the 

eastern  United  States;  C.  latifolia 
(Trev.)  Griseb.,  with  open  panicle 
and  spikelets  4  mm.  long,  grows  in 
damp  woods  across  the  continent  in 
the  northern  part  of  the  United  States, 
mostly  at  medium  and  high  elevations. 


Both  species  furnish  ex- 
cellent forage,  but  are  usu- 
ally not  abundant  enough 
to  be  of  much  importance. 

60.  LIMNODEA  L.  H.  Dewey. 

Spikelets  1-flowered, 
disarticulating  below  the 
glumes,  the  rachilla  pro- 
longed behind  the  palea  as 
a  short,  slender  bristle; 
glumes  equal,  firm;  lemma 
membranaceous.  smooth, 

FIG.  72. — Wood  reed-grass,  Cinna  arundinacea.  ,  '.,      _  . 

Plant,  x  i ;  spikeiet  and  floret,  x  5.       nerveless,  2-tootned  at  the 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES. 


135 


apex,  bearing  from  between  the  teeth  a  slender  bent  awn,  twisted  at 
base ;  palea  a  little  shorter  than  the  lemma. 

A  slender  annual  with  flat  blades  and  narrow  panicles.     Species 

one,  Florida  to  Texas. 

Type  species :  Greenia  arkansana 
Nutt. 

Greenia  Nutt.,  Trans.  Amer.  Phil.  Soc. 
5:  142,  1837,  not  Greenea  Wight  and 
Arn.,  1834.  Type  O.  arkansana,  the  only 
species  described. 

Sclerachne  Torr. ;  Trin.,  Mem.  Acad. 
St.  PStersb.  VI.  Sci.  Nat.  41:  273,  1841, 
not  Sclerachne  R.  Br.  and  Benn.,  1838. 
Two  species  are  described,  S.  arkansana 
Torr.  and  8.  pilosa  Trin.  The  first, 
based  on  Greenia  arkansana  Nutt.,  is 
the  type. 

Thurberia  Benth.,  Journ.  Linn.  Soc. 
Bot.  19:  58,  1881,  not  Thurberia  A. 
Gray,  1854.  Type  Greenia  arkansana 
Nutt.,  the  name  Thurberia  being  substi- 
tuted for  Greenia. 

Limnodea  L.  H.  Dewey,  Contr.  U.  S. 
Nat.  Herb.  2:  518.  1894.  Only  one  spe- 
cies described. 

Limnodea  arkansana 
(Nutt.)  L.  H.  Dewey 
(fig.  73),  has  probably 
no  agricultural  value. 
A  form  with  pilose 


t 


FIG.  73. — Limnodea  arkansana.     Plant,   X   I  ;  spikelet  and  floret,   X   5. 


136          BULLETIN  772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


glumes  has  been  named 
L.  arkansana  pilosa  (Trin.) 
Scribn. 

61.  ALOPECURUS    L.,     the    meadow 
foxtails. 

Spikelets  1 -flowered,  disar- 
ticulating below  the  glumes, 
strongly  compressed  laterally; 
glumes  equal,  awnless,  usually 
united  at  base,  ciliate  on  the 
keel;  lemma  about  as  long 
as  the  glumes,  5-nerved,  ob- 
tuse, the  margins  united  at 
base,  bearing  from  below 
the  middle  a  slender  dorsal 
awn,  this  included  or  ex- 
serted  two  or  three  times  the 
length  of  the  spikelet;  palea 
wanting. 

Low  or  moderately  tall  per- 
ennial grasses  with  flat  blades 
and  soft,  dense,  spikelike  pan- 
icles. Species  about  25,  in  tem- 
perate regions  of  the  North- 


FIG.  74. — Meadow  foxtail,  Alopecurus  pratensis.    Plant,  X   I  ;  spikelet  and  floret,  X  5. 

ern    Hemisphere.    Of    the    eight    North    American    species,    two 
are  introductions  from  Europe  and  two  are  widely  distributed  in 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  137 

Eurasia.     Some  of  the  European  species  with  a  distinct  palea  have 
been  segregated  as  the  genus  Colobachne. 

Type  species:  Alopecurus  pratensis  L. 

Alopecurus  L.,  Sp.  PI.  60,  1753;  Gen.  PL,  ed.  5,  30.  1754.  Four  species  are 
described,  A.  pratensis,  A.  geniculatus,  A.  hordciformis,  and  A.  monspeliensis. 
The  third  and  fourth  species  do  not  agree  with  Linnseus's  generic  description 
and  are  now  referred,  the  third  to  Pennisetum  and  the  fourth  to  Polypogon. 
The  other  two  were  well  known  to  Linnaeus  and  were  described  in  his  flora  of 
Sweden.  The  first,  being  an  economic  species,  is  chosen  as  the  type  species  of 
the  genus. 

Alopecurus  pratensis  L.  (fig.  74),  meadow  foxtail,  is  sometimes 
used  as  a  meadow  grass  in  the  eastern  United  States.  It  is  recom 
mended  for  mixtures  on  moist  soil,  being  nutritious  and  producing 
early  forage.  Meadow  foxtail  is  an  erect  grass,  2  to  3  feet  tall,  with 
short  rhizomes,  loose,  often  inflated,  sheaths,  and  spikes  or  heads  2 
to  4  inches  long  and  about  one-fourth  of  an  inch  thick.  Introduced 
from  Europe,  where  it  is  favorably  known  as  a  meadow  grass. 

Alopecurus  geniculatus  L.  is  a  low,  pale,  soft  grass,  usually  6  to  18 
inches  high,  with  decumbent  rooting  bases  and  slender  panicles  1  to 
3  inches  long  and  about  one-eighth  of  an  inch  thick,  the  delicate  awn 
bent  and  protruding  about  twice  the  length  of  the  spikelet.  Found 
in  moist  places  across  the  continent.  An  allied  and  more  common 
species,  A.  aristulatus  Michx.  (A.  geniculatus  aristulatus  (Michx.) 
Torr.),  is  distinguished  by  the  scarcely  exserted  awns.  Alopecurus 
alpinus  J.  E.  Smith  (A.  occidentalis  Scribn.),  a  northern  species 
extending  into  the  Rocky  Mountains  of  the  United  States,  has  a 
short,  thick  spike  with  spikelets  woolly  all  over.  Alopecurus  cali- 
fornicus  Vasey,  of  the  northwestern  Pacific  coast  region,  has  slender 
spikes,  1  to  3  inches  long  and  one- fourth  of  an  inch  thick,  the  spike- 
lets  3  mm.  long.  The  species  of  Alopecurus  are  all  palatable  and- 
nutritious,  but  usually  are  not  found  in  sufficient  abundance  to  be  of 
great  importance. 

62.  POLYPOGON  Desf. 

Spikelets  1-flowered,  the  pedicel  disarticulating  a  short  distance 
below  the  glumes,  leaving  a  short-pointed  callus  attached;  glumes 
equal,  entire  or  2-lobed,  awned  from  the  tip  or  from  between  the 
lobes,  the  awn  slender,  straight ;  lemma  much  shorter  than  the  glumes, 
hyaline,  usually  bearing  a  slender  straight  awn  shorter  than  the 
awns  of  the  glumes. 

Annual  or  perennial  usually  decumbent  grasses,  with  flat  blades 
and  dense,  bristly,  spikelike  panicles.  Species  about  10,  in  the  tem- 
perate regions  of  the  world,  chiefly  in  the  Eastern  Hemisphere,  three 
species  being  introductions  into  the  United  States. 

Type  species :  Alopecurus  monspeliensis  L. 

Polypogon  Desf.,  Fl.  Atlant.  1:  66.  1798.  Only  one  species  described,  this 
based  on  Alopecurus  monspeliensis  L. 


138          BULLETIN  772,  U.   S.   DEPARTMENT  OF  AGRICULTURE. 


Polypogon  lutosus  (Poir.)  Hitchc.  (Agrostis  lutosa  Poir.,  P.  lit 
tordlis  J.  E.  Smith,  based  on  Agrostis  littoralis  With.,  1796,  not  Lam. 
1791),  a  perennial 
with  awns  scarcely 
longer  than  the 
glumes,  is  frequent 
on  the  Pacific  coast. 
Polypogon  monspeli- 
ensis  (L.)  Desf.  (fig. 
75)  is  an  annual  with 
soft,  bristly,  green  or 
yellowish  spikes  1  to 
6  inches  long,  the 
awns  much  longer 
than  the  glumes. 
This  is  a  common 
weed  on  the  Pacific 
coast  and  is  occa- 
sional in  the  Atlantic 


\ 


FIG.  75. — Polypogon  monspeliensis.     Plant,  X   I  ;  spikelet  and  floret,  X  5. 

States.  Polypogon  maritimus  "Willd.  is  a  rare  species  found  in 
Georgia  and  California,  and  differs  from  the  preceding  in  having 
deeply  lobed  lemmas,  the  lobes  ciliate.  Our  species  are  relished  by 


GENEKA  OF   GRASSES   OF   THE   UNITED  STATES. 


139 


stock,  and  P.  monspeliemis  is  sometimes  sufficiently  abundant  on  low 
meadows  to  be  of  importance. 

63.  LYCURUS  H.  B.  K. 


Spikelets  1-flowered,  the  rachilla 
articulate  above  the  glumes;  glumes 
awned,  the  -first  usually  2-awned; 
lemma  narrow,  firm,  longer  than  the 
glumes,  terminating  in  a  slender  awn. 

Low  perennial  grasses,  with  dense 
spikelike  panicles,  the  spikelets  borne 
in  pairs,  the  lower  of  the  pair  sterile, 
the  short  branchlets  deciduous.  Spe- 
cies two,  in  arid  regions  from  the 
southwestern  United  States  to  north- 
ern South  America. 

Type  species :  Lycurus  phleoides  H.  B.  K. 

Lycurus  H.  B.  K.,  Nov.  Gen.  and  Sp.  1: 
141,  pi.  45.  1816.  Two  species  are  described, 
L.  phleoides  and  L.  phalaroides.  The  first 
species,  being  figured,  is  chosen  as  the  type. 

Pleopogon  Nutt,  Journ.  .Acad.  Nat.  Sci. 
Phila.  II.  1:  189.  1848.  A  single  species, 
P.  setosum,  is  included.  This  is  Lycurus 
phleoides. 

Lycuvus  phleoides  (fig.  76),  the 
only  species  in  the  United  States,  is  a 
low  bunch-grass  with  slender  erect 
culms  about  a  foot  high,  with  a  dense, 
narrow,  lead-color  panicle  1  or  2 
inches  long.  The  species,  sometimes 
called  Texas  timothy  and  wolftail,  is 
common  on  the  Mexican  Plateau  and 


FIG.  76. — Wolftail,  Lycurus  phleoides. 
Plant,  X  2  ;  group  of  two  spikelets, 
glumes  of  fertile  spikelet,  and  two 
views  of  fertile  floret,  X  5. 


extends  north  to  Texas,  Colorado,  and  Arizona.    It  is  often  an  im- 
portant constituent  of  grazing  areas. 


140  BULLETIN   772,   IT.   S.    DEPARTMENT   OF   AGRICULTURE. 


64.  PHLEUM  L. 

Spikelets  1-flowered,  laterally  compressed,   disarticulating  above 

the  glumes ;  glumes  equal, 
membranaceous,  keeled, 
abruptly  mucronate  or 
awned ;  lemma  shorter 
than  the  glumes,  hyaline, 
broadly  truncate,  3  to  5 
nerved;  palea  narrow, 
nearly  as  long  as  the 
lemma. 

Annuals  or  perennials, 
with  erect  culms,  flat 
blades,  and  dense,  cylin- 
dric  panicles.  About  10 
species,  in  the  temperate 
regions  of  both  hemi- 
spheres. 

Type  species :  Phleum  pra- 
tense  L. 

Phleum  L.,  Sp.  PI.  59,  1753  ; 
Gen.  PI.,  ed.  5,  29.  1754. 
Four  species  are  described, 
P.  pratense,  P.  alpinum,  P. 
arenarium,  and  P.  schoe- 
noides.  The  first  species 
is  chosen  as  the  type  because 
it  is  the  only  cultivated  spe- 
cies in  the  genus.  The  first 
three  species  are  still  re- 
tained in  Phleum  ;  the  fourth 
is  referred  to  Heleochloa. 

Stelephuras  Adans.,  Fam. 
PI.  2:  31.  607.  1763.  Based 
on  Phleum  L. 

Four  species  of  Phleum 
are  found  in  the  United 
States.  Our  only  native 
species  is  P.  alpinum  L., 
mountain  timothy,  a  per- 
ennial with  short  spikes, 
two  or  three  times  as 
long  as  wide,  found  in 
the  northern  regions  of 
Eurasia  and  America  and 
extending  south  in  the 
mountains  of  Xew  Eng- 
land, in  the  Rocky  Moun- 
tains to  Mexico,  and  in 
the  Sierra  Nevada  and 
Coast  Ranges  to  the  San 

FIG.    77. — Timothy,   Phleum   pratense.      Plant,    X    i  I      T      .  ,.-  . 

spikelet  and  floret,   X   5.  JaCintO  Mountains. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  141 

Mountain  timothy  produces  a  fair  amount  of  nutritious  forage, 
which  remains  green  till  late  in  the  season  and  is  considered  a  valu- 
able late  sheep  feed.  It  is  an  important  constituent  of  mountain 
meadows.  This  species  is  distinguished  from  common  timothy  by  the 
shorter,  broader  heads  and  by  the  absence  of  the  swollen  base  of  the 
stem  or  so-called  bulb.  Two  species,  P.  graecum  Boiss.  and  Heldr. 
and  P.  bellardi  Willd.,  are  annuals  introduced  from  Europe  and 
found  here  only  at  a  few  coast  points  on  dumping  grounds  for  ballast. 

The  fourth  species  is  timothy,  PHlewn  pratense  L.  (PL  XIV;  fig. 
77),  an  erect,  short-lived  perennial,  2  to  4  feet  tall,  with  elongate 
cylindric  inflorescences  or  "  heads  "  several  times  longer  than  broad. 
The  stems  are  swollen  at  the  base,  and  the  glumes,  like  those  of  moun- 
tain timothy,  are  ciliate  on  the  keel.  Timothy,  a  native  of  Europe 
and  northern  Asia,  is  now  commonly  cultivated  in  this  country  and 
in  Europe  as  a  meadow  grass,  and  is  found  growing  without  culti- 
vation in  waste  places,  roadsides,  and  old  fields  throughout  most  of 
the  United  States.  It  is  the  most  important  meadow  grass  grown  in 
America,  and  timothy  hay  is  the  standard  for  all  grass  hay  sold  on 
the  market.  The  region  of  the  United  States  favorable  for  the  grow- 
ing of  timothy  is  the  crop  area  known  as  the  cool  humid  region,  which 
includes  the  northeastern  portion  west  to  the  Great  Plains  and  south 
to  Virginia  and  Missouri,  or  farther  in  the  mountains.  Another 
timothy  area  is  found  on  the  Pacific  coast  from  northern  California 
to  Puget  Sound.  Much  timothy  is  grown  in  favorable  localities  in 
the  western  mountains.  In  some  localities  timothy  is  known  as  herd's- 
grass. 

See  Evans,  U.  S.  Dept.  Agr.,  Farmers'  Bull.  502,  1912;  McClure, 
U.  S.  Dept.  Agr.,  Farmers'  Bull.  508,  1912;  Williams,  U.  S.  Dept. 
Agr.  Yearbook,  1896:  147,  1897;  Scribner,  U.  S.  Dept.  Agr.,  Div. 
Agrost.  Bull.  20:  fig.  47.  1900. 

65.  GASTRIDIUM  Beauv. 

Spikelets  1-flowered,  the  rachilla  disarticulating  above  the  glumes, 
prolonged  behind  the  palea  as  a  minute  bristle ;  glumes  unequal,  some- 
what enlarged  or  swollen  at  the  base ;  lemma  much  shorter  than  the 
glumes,  hyaline,  broad,  truncate,  awned  or  awnless;  palea  about  as 
long  as  the  lemma. 

Annual  grasses,  with  flat  blades  and  pale,  shining,  spikelike  pan- 
icles. Species  two,  in  the  Mediterranean  region ;  one  introduced  into 
the  United  States. 

Type  species :  M ilium  lendigerum  L. 

Gastridium  Beauv.,  Ess.  Agrost.  21,  pi.  6,  f.  6.  1812.  Beauvois  mentions 
only  one  species,  Milium  lendigerum,  but  the  description  of  the  plate  bears  the 
name  Gastridium  australe. 


142  BULLETIN   772,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 


Gastridium  ventricosum   (Gouan)    Schinz  and  Thell.1    (G.  lendi- 
gerum  (L.)  Gaud.)  (fig.  78),  with  an  awned  lemma,  a  common  weed 

on  the  Pacific  coast,  appears 
to  have  no  economic  value. 


66.  LAGUBUS  L. 

Spikelets  1-flowered,  the 
rachilla  disarticulating  above 
the  glumes,  pilose  under  the 
floret,  produced  beyond  the 
palea  as  a  bristle;  glumes 
equal,  thin,  1-nerved,  villous, 
gradually  tapering  into  a 
plumose  aristiform  point; 
lemma  shorter  than  the 
glumes,  thin,  glabrous,  bear- 
ing on  the  back  above  the 
middle  a  slender,  exserted, 
somewhat  geniculate,  dorsal 
awn,  the  summit  bifid,  the 
divisions  delicately  awn- 
tipped;  palea  narrow,  thin, 
the  two  keels  ending  in 
minute  awns. 

An  annual  grass,  with  pale, 
dense,  ovoid  or  oblong  woolly 
heads.  Species  one,  in  the 
Mediterranean  region  and  in- 
troduced sparingly  in  Cali- 
fornia. 

Type  species :  Lagurus  ovatus  L. 

Lagurus  L.,  Sp.  PL  81,  1753; 
Gen.  PI.,  ed.  5,  34.  1754.  Only 
one  species  described. 

Lagurus  ovatus  (fig.  79)  is 
sometimes  cultivated  as  an 
ornamental,  the  woolly  heads 
being  used  for  dry  bouquets. 

67.  EPICAMPES  Presl. 

Spikelets  1-flowered,  the 
rachilla  disarticulating  above 

1  This  name  is  based  on  Agrostis 
ventricosa  Gouan,  Hort.  Monsp.  39,  pi. 
1,  f.  2,  1762,  which  was  published 
earlier  in  the  year  than  Milium  lendi- 
gcrum  L.,  Sp.  PI.,  ed.  2,  91,  1762,  as 
shown  by  Linnaeus's  reference  to 
Gouan's  work  in  the  preface  to  the  sec- 
ond edition  of  his  Species  Plantarum. 


FIG.  78. — Gastridium  vcntricosum.     Plant,   X 
spikelet   and   floret,    X    5. 


GENERA  OF  GRASSES   OF  THE   UNITED  STATES. 


143 


the  glumes;  glumes  about  equal;  lemma  equaling  or  longer  than  the 
glumes,  3-nerved,  often  bearing  a  slender  awn  just  below  the  tip. 


FIG.  79. — Hare's-tail  grass,  Lagurus  ovatus.     Plant,   X    I ;  spikelet  and  floret,   X    5. 

Tall  cespitose  perennials,  with  open,  narrow,  or  spikelike  panicles. 
Species  15,  northern  South  America  to  Mexico,  5  extending  into  the 
southwestern  United  States. 


144  BULLETIN  772,  U.   S.   DEPARTMENT  OF  AGRICULTURE. 


Type  species :  Epicampes  strictus  Presl. 

Epicampes  Presl,  Rel.  Haenk.  1:  235,  pi.  39.  1830.  Only  one  species  de- 
scribed. 

Crypsinna  Fourn.,  Mex.  PI.  2:  90.  1SS6.  Three  species  are  mentioned, 
C.  stricta,  C.  macroura,  and  C.  setifolia.  In  the  generic  description  the  panicle 

is  said  to  be  densely 
spiciform.  This  applies 
best  to  the  second  spe- 
cies, C.  macroura,  which 
is  chosen  as  the  type. 

One  species,  Epi- 
campes rigens  Benth. 
(fig.  80),  with  long, 
slender,  cylindric, 
pale,  spikelike  pan- 
icles, the  glumes 
shorter  than  the 
lemma,  is  found  from 
western  Texas  to 
southern  California. 
This  species,  called 
deer-grass,  and  the 
four  other  species,  E. 
ligulata  Scribn.,  E. 
berlandieri  Fourn.,  E. 
subpatens  Hitchc.,1 
and  E.  emersleyi 


1  Epicampes  subpatens,  n.  sp. 
Culms  erect,  glabrous,  50 
to  100  cm.  tall ;  sheaths 
glabrous,  slightly  scabrous, 
compressed-keeled,  especially 
those  of  the  innovations ; 
ligule  softly  membranace- 
ous,  1  to  2  cm.  long ;  blades 
flat  or  folded,  scabrous,  1 
to  3  mm.  wide,  the  lower 
as  much  as  50  cm.  long ; 
panicles  narrow  but  rather 
loose,  mostly  20  to  40  cm. 
long,  the  branches  ascend- 
ing, more  or  less  fascicled 
or  whorled,  naked  below ; 
spikelets  about  3  mm.  long, 


FIG.  80. — Deer-grass,  Epicampes  ricfcns.     Plant,   X   I  ;  spikelet  and  floret,  X  5. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  145 

(Vasey)  Hitchc.  (Muhlenbergia  emersleyi  Yasey,  M.  vaseyana 
Scribn.) ,  are  forage  grasses.  A  Mexican  species,  E.  macrowa  Benth., 
is  of  considerable  economic  importance,  the  roots  being  used  in  the 
manufacture  of  scrubbing  brushes. 

68.  MUHLENBEBGIA  Schreb. 

Spikelets  1-flowered,  the  rachilla  disarticulating  above  the  glumes; 
glumes  usually  shorter  than  the  lemma,  obtuse  to  acuminate  or 
awned,  the  first  sometimes  small  or  rarely  obsolete;  lemma  firm- 
membranaceous,  3  to  5  nerved,  with  a  very  short,  usually  minutely 
pilose  callus,  the  apex  acute,  sometimes  bidentate,  extending  into  a 
straight  or  flexuous  awn,  or  sometimes  only  mucronate. 

Perennial  or  rarely  annual  low  or  moderately  tall  grasses,  tufted 
or  rhizomatous,  the  culms  simple  or  much  branched,  the  in- 
florescence a  narrow  or  open  panicle.  Species  about  80,  mostly  in 
Mexico  and  the  southwestern  United  States,  a  few  in  the  eastern  part 
of  the  Old  World ;  40  species  in  the  United  States. 

Type  species:  Muhlenbergia  schreberi  Gmel. 

Muhlenbergia  Gmel.,  Syst.  Nat.  2 :  171.    1791.    Only  one  species  mentioned. 

Dilepyrum  Michx.,  Fl.  Bar.  Amer.  1 :  40.  1803.  '  Two  species  are  described, 
D.  urixtomun,  which  is  Brachyelytrum  erectum,  and  D.  minutiflorum,  which  is 
MuMenbergfa  schreberi  Gmel.  They  are  equally  eligible  as  the  type.  The 
second  is  chosen,  in  order  to  conserve  the  generic  name  Brachyelytrum. 

Podosemum  Desv.,  Nouv.  Bull.  Soc.  Philom.  Paris  2 :  188.  1810.  The  type  is 
Stipa  capillaris  Lam.  (P.  capillaris  Desv.),  the  only  species  mentioned. 

Olomena  Beauv.,  Ess.  Agrost.  28,  pi.  7,  f.  10.  1812.  The  type  is  C.  peruviana, 
the  only  species  mentioned.  This  is  Muhlenbergia  peruviana  (Beauv.)  Steud. 

Trichochloa  Beauv.,  Ess.  Agrost.  29,  pi.  8,  f.  2.     1812.     The  type  and  only 
species  is  T.  purpurea.    This  has  not  been  identified.     Roemer  and  Schultes 
say  it  is  Trichochloa  expansa  DC.  (Muhlenbergia  expanse  (DC.)  Trin.). 

Tosagris  Beauv.,  Ess.  Agrost.  29,  pi.  8,  f.  3.  1812.  The  type  is  T.  agrostidea, 
the  only  species  mentioned.  This  has  not  been  identified,  but  it  appears  to  be 
a  species  of  Muhlenbergia. 

Sericrostis  Raf.,  Neogenyt.  4.  1825.  "Type  Stipa  sericea  MX.  or  diffusa 
Walter."  This  is  Muhlenbergia  capillaris  (Lam.)  Trin. 

Calycodon  Nutt,  Journ.  Acad.  Phila.  II.  1:  186.  1848.  The  type  is  C.  mon- 
tanum  (Muhlenbergia  montana  Hitchc.),  the  only  species  described. 

Vaseya  .Thurb.,  in  Gray,  Proc.  Acad.  Phila.  1863 :  79.  1863.  The  type  is 
V.  comata  Thurb.,  the  only  species  described.  This  is  Muhlenbergia  andina 
(Nutt.)  Hitchc.  (Calamag'rostis  andina  Nutt). 

often  tinged  with  purple ;  glumes  about  as  long  as  the  lemma,  papery,  acutish, 
scabrous ;  lemma  narrowed  and  scabrous  abovo,  villous  below,  awnless,  or  occasionally 
those  of  a  few  of  the  spikelets  with  a  flexuous  awn  about  1  cm.  long. 

Type,  U.  S.  National  Herbarium  no.  905799,  collected  in  a  rocky  ravine,  Guadeloupe 
Mountains,  near  Queen,  N.  Mex.,  altitude  7,000  feet,  Sept.  5,  1915,  by  A.  S.  Hitchcock, 
no.  13541. 

This  species  is  closely  allied  to  Epicampes  emersleyi,  from  which  it  differs  in  the  awn- 
less  spikelets  and  larger,  looser,  and  more  spreading  panicles.  The  writer  examined  the 
two  forms  in  the  Guadeloupe  Mountains,  southern  New  Mexico,  and  concluded  from  these 
field  observations  that  the  awned  and  awnless  forms  represented  two  distinct  but  closely 
allied  species.  The  delicate  awns  are  not  noticeable  at  a  distance  but  the  more  open 
panicle  was  always  found  to  be  associated  with  the  awnless  spikelets. 

Other  specimens  in  the  U.  S.  National  Herbarium. — TEXAS  :  Limpia  Canyon,  Nealley 
133.  Chisas  Mountains,  Bailey  392.  Guadeloupe  Mountains,  Bailey  739.  Western  Texas, 
Wright  729.  NEW  MEXICO  :  Socorro,  Plank  53.  Silver  City,  Greene  439.  ARIZONA  : 
Patagonia,  Hitchcock  3719.  Chiracahua  Mountains,  Tourney  15a.  Santa  Catalina  Moun- 
tains, Griffiths  7149. 

1  Syst.  Veg.  2  :  384.     1817. 

97769°— 19— Bull.  772 10 


146  BULLETIN   772,   U.    S.   DEPARTMENT   OF   AGRICULTURE. 

Chaboissnea  Fourn.,  Mex.  PI.  2:  112.  1886.  A  single  species,  C.  ligulata,  is 
included.  This  is  Muhlenbergia  ligulata  (Fourn.)  Scribn.  and  Merr. 

Muhlenbergia  is  a  somewhat  artificial  genus,  including  species  of 
very  diverse  habit.  It  differs  from  Sporobolus  in  the  3-nerved  awned 
or  mucronate  lemma,  and  from  Agrostis  in  the  firmer  lemma,  usually 
longer  than  the  glumes.  One  group,  including  M.  squarrosa  (Trin.) 
Rydb.  (fig.  81),  M.  repens  (Presl)  Hitchc.,  and  their  allies,  has  been 
usually  referred  to  Sporobolus.  The  species  of  this  group  are  in- 
cluded in  Muhlenbergia  because  of  the  3-nerved  mucronate  or  awned 
lemmas,  but  they  form  a  distinct  section  or  possibly  a  distinct  genus. 


FIG.  81. — Muhlenbergia,  squarrosa.     Plant,   X   \  ;  spikelet  and  floret,   X  5. 

In  M.  repens  the  lateral  nerves  of  the  lemma  are  commonly  obsolete, 
and  the  apex  is  sometimes  scarcely  mucronate. 

Of  the  species  found  in  the  United  States  two  are  annuals,  M.  de- 
pauperata  Scribn.,  with  acuminate  or  awned  glumes,  and  M.  micro- 
sperma  (DC.)  Kunth,  with  obtuse  glumes,  both  growing  in  the  ex- 
treme Southwest.  The  latter  species  produces  cleistogenes  in  the  axils 
of  the  lower  sheaths.  Muhleiibergia  mexicana  (L.)  Trin.  and  its 
allies  have  branching  stems  and  numerous  panicles.  The  glumes  are 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES. 


147 


reduced  in  M.  schreberi  (fig.  82),  the  type  species,  the  first  being 
obsolete  and  the  second  not  over  0.5  mm.  long.  In  M.  montana 
(Nutt.)  Hitchc.  (Calycodon  montanum  Nutt ;  Muhleribergia  trifida 

Hack. ;  M.  gradlis 
of  authors,  not 
H.  B.K.)  the  sec- 
ond glume  is  3- 
toothed.  Muhlen- 
bergia  capillaris 
(Lam.)  Trin.  (fig. 
83),  of  the  South- 
ern States,  is  a 
handsome  peren- 
nial with  diffuse 
purple  panicles. 
There  are  nine 
species  in  the 
Eastern  States; 
the  others  are 
western  or  mainly 
southwestern. 
Many  of  the  west- 
ern species  are 
important  range 
grasses  and  often 
form  a  consider- 
able proportion  of 
the  grass  flora  of 
the  arid  and  semi- 
arid  regions.  The 
commonest  of 
these  are  M.  mon- 
tana and  M. 
wrightii  V  a  s  e  y. 
The  second  has  a 
spikelike  leaden- 
hued  panicle. 


FIG.  82. — Nimble  Will,  Muhlenbergia  schreberi.  Plant,  X  I  ;  branchlet  showing  both  first 
ana  second  glumes  of  two  spikelets,  spikelet  with  obsolete  first  glume,  and  floret,  all 
X  5. 


148          BULLETIN  772,  U.  S.  DEPARTMENT  OF  AGRICULTURE. 


FIG.  83.— Muhlenbergia  capillaris.    Plant,  X  I ;  spikelet,  X  5. 


GENERA  OF  GRASSES   OF  THE   UNITED  STATES. 


149 


69.  SPOROBOLUS  R.  Br. 


Spikelets  1-flowered,  the  rachilla  disarticulating  above  the  glumes; 
glumes  awnless,  usually  unequal,  the  second  often  as  long  as  the  spike- 
let;  lemma  membranaceous,  1-nerved, 
awnless;  palea  usually  prominent  and 
as  long  as  the  lemma  or  longer;  seed 
free  from  the  pericarp. 

Annual  or  perennial  grasses,  with 
small  spikelets  in  open  or  contracted 


PIG.   84. — Smut-grass,  Sporobolus  berteroanus.     Plant,    X    i  ;   spikelet  and  floret,    X    5. 


150          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

panicles.    Species  about  95,  in  the  warm  regions  of  both  hemispheres, 
most  abundant  in  America ;  36  species  in  the  United  States. 

Type  species :  Agrostis  indica  L. 

Sporobolus  R.  Br.,  Proclr.  Fl.  Nov.  Holl.  169.  1810.  Three  species  are  de- 
scribed, &  indicus,  8.  elongatus,  and  8.  pulchellus.  Brown  states  that  Sporobo- 
lus includes  Agrostis  species  of  Linnaeus.  Of  the  three  species  described  by 
Brown  only  the  first  was  known  to  Linnaeus  and  included  by  him  under  Agrostis. 
Hence  the  first  species  is  chosen  as  the  type. 

Agrosticula  Raddi,  Agrost.  Bras.  33,  pi.  1,  f.  2.  1823.  Type  A.  muralis,  the 
only  species  described. 

Bennetia  Raf.,  Bull.  Bot.  Seringe  1:  220.  1830.  Afirostis  jmicea  Michx.  is 
the  only  species  included.  This  is  Sporobolus  gracilis  (Trin.)  Merr. 

Crystostachys  Stend..  Syn.  PI.  Glum.  1:  181.  1854.  The  type  is  C.  rapinata. 
the  only  species  described.  From  the  description  this  appears  to  be  Sporobolus 
vaginaeflorus. 

Bauchea  Fourn..  Mex.  PI.  2:  87.  1886.  Type  B.  karwinskyi,  the  only  species 
described.  This  is  Sporobolus  u:rightii. 

The  fruit  is  free  from  the  lemma  and  palea,  and  falls  readily  from 
the  spikelet  at  maturity.  Because  of  this  character  the  species  have 
been  called  drop-seed  grasses.  The  genus  differs  from  Muhlenbergia 
in  having  1 -nerved  awnless  lemmas  and  from  Agrostis  in  having 
lemmas  as  long  as  the  glumes  or  longer  and  as  firm. 

Four  species  of  the  United  States  are  annual.  One  of  them, 
Sporobolus  vaginae-flams  (Torr.)  Wood,  is  called  poverty  grass, 
because  it  grows  in  sterile  soil.  This  has  narrow  panicles,  partly  or 
wholl}'  inclosed  in  the  sheaths.  Several  of  the  perennial  species  have 
creeping  rhizomes.  One  of  these,  S.  virginicus  (L.)  Kunth,  is  a 
common  seashore  grass  in  the  Southern  States.  It  has  erect  stems 
6  to  10  inches  tall,  with  spikelike  panicles  of  pale  spikelets.  The 
other  species  of  the  genus  are  erect  bunch-grasses.  Sporobolus  ~ber- 
teroanus  (Trin.)  Hitchc.  and  Chase  (fig.  84),  with  long,  slender, 
spikelike  panicles,  is  common  in  the  Southern  States  (S.  indicus 
of  the  manuals,  not  S.  indicus  (L.)  R.  Br.).  This  species  is 
called  smut-grass,  because  the  inflorescence  is  frequently  affected 
with  a  black  fungus.  The  glumes  are  about  equal  and  much 
shorter  than  the  lemma.  Sporobolus  wyptandrus  (Torr.)  Gray 
(fig.  85)  is  common  on  sandy  soil,  especially  in  the  interior  of 
the  country.  This  has  very  small  spikelets  in  panicles  sometimes 
partly  inclosed  in  the  upper  sheath,  only  the  upper  portion 
spreading,  or  even  entirely  inclosed  in  the  swollen  sheaths.  There 
is  a  conspicuous  tuft  of  hairs  at  the  summit  of  the  sheaths.  In 
winter  the  leaves  and  stems  become  fibrous  and  much  frayed  out  by 
the  wind. 

Two  species  of  the  Southwest  are  important  forage  grasses  in  the 
arid  and  semiarid  regions.  Sporobolus  cdroides  Torr.  (fig.  86), 
growing  in  dense,  tough  clumps,  the  stems  1  or  2  feet  high,  and  with 
large  spreading  panicles,  is  found  on  somewhat  alkaline  soil  and  is 
called  bunch-grass  or  alkali  saccaton.  It  ranges  from  Nebraska  to 


GENERA  OF  GRASSES   OF  THE   UNITED  STATES. 


151 


Montana  and  Texas.  Sporobolus  wrigJitii  Munro,  saccaton ,  is  much 
taller,  with  a  large  but  narrow  panicle.  This  is  found  from  Arizona 
to  western  Texas. 

Most  of  the  per- 
ennial species  of 
Sporobolus  are  pal- 
atable forage, 
grasses,  but  few7  of 
them  are  abundant 
enough  to  be  of  im- 
portance. On  the 
Arizona  Plateau,  S. 
interruptus  Vasey 
is  an  important 
range  grass.  It  is 
called  black  sporo- 
bolus,  because  of 
the  dark,  narrow, 
loosely  flowered 
panicle. 

70,    BLEPHARONETJKON 
Nash. 

Spikelets  1 -flow- 
ered, the  rachilla 
disarticu  lating* 
above  the  glumes; 
glumes  subequal, 
rather  broad; 
lemma  3-nerved, 
the  nerves  densely 
pilose  ;  palea 
densely  pilose  be- 
tween  the  two 
nerves. 

A  perennial  grass 
with  an  open,  nar- 
row panicle.  Spe- 
cies one ;  southwest- 
ern United  States 
and  northern  Mex- 
ico. 

Type  species:  Vilfa 
tricholcpis  Torr. 

Blepharo  neuron 
Nash,  Bull.  Torrey 
Club  25:  88.  1898. 
Only  one  species  men- 
tioned, B  tricholepiS  FIG.  85. — Saud  dropseed,  Nporo&oZus  cryptandrus.  Plant, 
(To»r.)  Nash.  X  i;  spikelet  and  floret,  the  palea  splitting,  X  5. 


152  BULLETIN   772,  U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  86  —Alkali  saccaton,  Sporobolus  air&ides.    Plant,  X  I ;  spikelet  and  floret,  X  5. 


GENERA  OP  GRASSES  OF  THE  UNITED  STATES. 


153 


The  single  species  (fig.  87)  is  a  tufted  grass  about  a  foot  high, 
found  on  open  or  rocky  soil  at  middle  altitudes  from  Colorado  to 
central  Mexico.  It  is  a  palatable  grass,  sufficiently  abundant  in  places 

to  be  of  importance.  Until  recent 
years  the  species  was  included  in 
Sporobolus. 

71.  CKYPSIS  Ait. 

Spikelets  1 -flowered,  the  rachilla 
disarticulating  below  the  glumes; 
glumes  about  equal,  narrow,  acute; 
lemma  broad,  thin,  awnless;  palea 
similar  to  the  lemma,  about  as  long, 
2-nerved,  readily  splitting  between 
the  nerves;  fruit  a  utricle,  the  seed 
free  from  the  thin  pericarp. 

A  spreading  annual,  with  capitate 
inflorescences  in  the  axils  of  broad 
bracts,  these  being  enlarged  sheaths 
with  short  rigid  blades.  Species 
one,  in  the  Mediterranean  region; 
sparingly  introduced  into  the  United 
States. 

Type  species:  Schoenus  aculeatus  L. 

Crypsis  Ait.,  Hort.  Kew.  1:  48.  1789. 
A  single  species  is  mentioned,  with  two 
varieties  or  forms,  a  (the  equivalent  of 
the  species),  based  on  Schoenus  aculeatus 
L.,  and  j3,  based  on  Phlewm  schoenoides 
L.  The  first  is  the  type. 

Bentham  and  Hooker1  state 
that  the  spikelet  has  four 
glumes  and  no  palea.  Hackel2 
states  that  the  palea  is  1-nerved. 
Our  specimens  show  an  evi- 
dently 2-nerved  palea. 


FIG.  87. — Blepharoneuron  tricholepis.     riant,    X    I  ;  spike- 
let  and  floret,   X   5. 


'Gen.  PI.  8:  1139.     1883. 


2Engl.  and  Prantl,  Pflanzenfam.  22:  48.     1887J_ 


154          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

Crypsie  acufoafa.  (L.)  Ait.  (fig.  88)  has  been  introduced  in  a  few 
places  in  California. 

72.  HELEOCHLOA  Host. 

Spikelets  1 -flowered,  the  rachilla  disarticulating  above  the  glumes; 
glumes  about  equal,  narrow,  acute;  lemma  broader,  thin,  a  little 
longer  than  the  glumes ;  palea  nearly  as  long  as  the  lemma,  2-nerved, 
readily  splitting  between  the  nerves ;  caryopsis  free  from  the  lemma 
and  palea. 

Low  perennial  spreading  grasses,  with  oblong,  dense,  spikelike 
panicles,  terminal  and  on  short  lateral  branches,  the  subtending  leaves 


FIG.  88. — Crypsis  aculeata.     Plant,   X    I  ;  spikelct  and  floret,  the  palea  splitting,    X    5. 

with  inflated  sheaths  and  reduced  blades.     Species  about  seven,  in 
the  Mediterranean  region,  one  introduced  into  the  United  States. 

Type  species :  Heleochloa  alopecuroides  Host. 

Heleochloa  Host,  Gram.  Austr.  1:  23.  1801.  Two  species  are  described, 
H.  alopecuroicles  and  H.  schoenoidcx,  both  of  which  are  figured.  The  first  is 
chosen  as  the  type. 

Heleochloa  schoenoides  (L.)  Host  (fig.  89)  has  been  introduced 
into  the  eastern  United  States  at  several  points  from  Massachusetts 
and  Delaware  to  Illinois. 

73.  BBACHYEJLYTBUM  Beauv. 

Spikelets  1 -flowered,  the  rachilla  disarticulating  above  the  glumes, 
prolonged  behind  the  palea  as  a  slender  naked  bristle;  glumes  very 
short,  unequal,  the  first  sometimes  obsolete,  the  second  sometimes 
awned ;  lemma  firm,  narrow,  5-nerved,  the  base  extending  into  a  pro- 


GENERA   OF   GRASSES   OF   THE   UNITED  STATES.  155 

nounced   oblique   callus,   the   apex   terminating   in   a   long   straight 
scabrous  awn. 

Perennial  erect,  slender  grasses,  with  short  knotty  rhizomes,  flat 
blades  and  narrow,  rather  few-flowered  panicles.  Species  one,  North 
American. 


\ 

FIG.  89. — Heleochloa  schoenoides.   Plant,  X  I  ',  spikelet  and  floret,  the  palea  splitting,  X  5. 

Type  species:  Muhlenbergia  erecta  Schreb. 

I.nichyelytrum  Beauv.,  Ess.  Ajri-ost.  .">!>.  pi.  9,  f.  2.     1812.     The  type  is  the 
figured  species,  B.  erectum,  based  011  Huhlenberyia  erecta. 


156          BULLETIN  772,  U.   S.  DEPARTMENT  OF  AGRICULTURE. 

Brachyelytrum  erectum  (Schreb.)  Beauv.  (fig.  90),  found  in 
rich  rocky  woods  in  the  northeastern  quarter  of  the  United  States,  is 
of  no  economic  importance.  It  has  been  known  also  as  B.  aristatum 
Beauv. 

74.  MILIUM  L. 

Spikelets  1-flowered,  disarticulating  above  the  glumes;  glumes 
equal,  obtuse,  membranaceous,  rounded  on  the  back;  lemma  a  little 
shorter  than  the  glumes,  obtuse,  awnless,  obscurely  nerved,  rounded 
on  the  back,  dorsally  compressed,  in  fruit  becoming  indurate,  smooth, 
and  shining,  the  margins  inclosing  the  lemma,  as  in  Panicum. 

Moderately  tall  grasses  with  flat  blades  and  open  panicloe.  Spe- 
cies about  six,  in- the  cooler  parts  of  Eurasia,  one  of  which  is  found 
also  in  northeastern  North  America. 

Type  species:  Milium  effusum  L. 

Milium  L.,  Sp.  PI.  61,  1753;  Gen.  PI.,  ed.  5,  30.  1754.  Two  species  are  de- 
scribed, M.  effusum  and  M.  confertum.  The  first  species  is  chosen  as  the  type 
as  it  was  the  one  best  known  to  Linnaeus,  being  described  in  his  flora  of  Sweden. 
The  second  species  is  now  reduced  to  a  variety  of  M.  effusum.  Milium  is  an 
ancient  Latin  name  for  the  common  millet  of  Europe  (Panicum  miliaceum  L. ). 
Linnaeus  applied  this  name  to  the  genus  above  described.1 

Milium  effusum  L.  (fig.  91) ,  millet  grass,  the  only  representative  of 
the  genus  in  America,  is  a  slender  erect  perennial  3  to  4  feet  tall, 
found  in  cool  woods  from  Nova  Scotia  to  Illinois.  It  is  of  no 
economic  importance. 

75.  ORYZOPSIS  Michx. 

Spikelets  1-flowered,  disarticulating  above  the  glumes;  glumes 
about  equal,  obtuse  or  acuminate;  lemma  indurate,  usually  about  as 
long  as  the  glumes,  broad,  oval  or  oblong,  nearly  terete,  usually 
pubescent,  with  a  short,  blunt,  oblique  callus,  and  a  short,  deciduous, 
sometimes  bent  and  twisted  awn ;  palea  inclosed  by  the  edges  of  the 
lemma. 

Perennial,  mostly  low  grasses,  with  flat  or  often  involute  blades 
and  terminal  narrow  or  open  panicles.  Species  about  20,  in  the  north 
temperate  regions  of  both  hemispheres;  13  species  in  the  United 
States. 

Type  species:  Oryzopsis  asperifolia  Michx.  (fig.  92). 

Oryzopsis  Michx.,  Fl.  Bor.  Amer.  1 :  51.    1803.    A  single  species  described. 

Dilepyrum  Raf.,  Med.  Repos.  5:  351.  1808.  Rafinesque  here  announces  a  new 
work  and  gives  the  names  of  several  proposed  new  genera  and  species.  One  of 
these  is  "Dilepyrum,  the  Orizopsis  of  do  [Michaux]."  The  type,  then,  is  Ory- 
zopsis  asperifolia  Michx. 

Piptatherum  Beauv.,  Ess.  Agrost.  17.  pi.  5,  f.  10.  1812.  Beauvpis  mentions 
five  species  and  figures  two,  P.  coerulescens  and  P.  punctatum.  Milium  coerules- 
cens,  the  basis  of  the  first  species,  is  chosen  as  the  type. 

Eriocoma  Nutt.,  Gen.  PI.  1:  40.  1818.  The  type  is  E.  cuspidata  Nutt.,  the 
only  species  described.  This  is  the  same  as  Oryzopsis  liymenoides. 

1  For  a  discussion  of  Milium  and  Panicum,  see  Hitchcock  and  Chase,  Contr.  U.  S.  Nat. 
Herb.  15:  11.  1910. 


GENERA  OF  GRASSES  OF  THE  UNITED  STATES.  157 


FIG.  90. — Brachyelytrum  erectum.    Plant,  X  1 ;  branchlet,  with  glumes  of  two  spikelets, 

and  floret,  X  5. 


158  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


Urachne  Trin.,  Fund.  Agrost.  109.  1820.  Trinius  cites  Beauvois's  two  figures 
mentioned  above,  which  represent  Piptatherum  coerulescens  and  P.  punctatum, 
and  at  the  end  of  his  generic  description  lists  three  species,  U.  coerulescens 

(M  ilium  coerulescens  Desf.),  U.  rircscens 
(Milium  paradoxum  Scop.),  and  U.  parviflora 
(Agrostis  miliacca  L.).  The  first  of  these  is 
chosen  as  the  type. 

Fendlera  Steud.,  Syn.  PI.  Glum.  1 : 419.  1854. 
Type,  F.  rhynclielytroides  Steud.,  the  only 
species  described.  This  is  the  same  as  Ory- 
zopsis  hymenoides. 

The  commonest  species  is  Oryzopsis 
hymenoides     (Roem.     and     Schult.) 
Kicker,   found  throughout  the  region 
west  of  the  Rocky  Mountains  on  dry 
soil.    This  has  an  open  divaricate  pani- 
cle  and    densely    long-silky    lemmas. 
The  species  of  Oryzopsis  are  grazed  by 
stock,  but  usually  are  not  in  suffi- 
cient abundance  to  be  of  impor- 
tance,   except    Indian    mountain 
rice  (O.  hynwnoides) . 

The  allied  Mexican  and  South 
American  genera,  Nasella  Desv. 
and  Piptochaetium  Presl,  differ  in 
having  an  obliquely  obovate  fer- 
tile lemma,  the  apex  gibbous,  and 
the  awn  eccentrically  attached. 

76.  STIPA  L.,  the  spear-grasses. 

Spikelets  1-flowered,  disarticu- 
lating above  the  glumes,  the  artic- 
ulation oblique,  leaving  a  .bearded, 
sharp-pointed  callus  attached  to 
the  base  of  the  floret ;  glumes  mem- 
branaceous,  often  papery,  acute, 


FIG.  91. — Millet  grass,  Milium  effusum.     Plant,   X   \  ',  spikelet  and  floret,   X   5. 

acuminate  or  even  aristate,  usually  long  and  narrow ;  lemma  narrow, 
terete,  firm  or  indurate,  strongly  convolute,  terminating  in  a  usually 
bent  and  twisted,  prominent,  persistent  awn;  palea  inclosed  in  the 
convolute  lemma. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  159 

Perennial  grasses,  with  usually  convolute  blades  and  narrow  pan- 
icles. Species  about  100,  in  the  temperate  regions  of  the  world, 
especially  on  plains  and  steppes;  30  species  in  the  United  States, 
mostly  in  the  western  part. 


Type  species :  Stipa  pennata  L. 

Stipa  L.,  Sp.  1M.  78,  1753 ;  Gen.  PI.,  ed.  5,  34.  1754.  Limireus  describes  three 
species,  £.  pennata,  8.  juncea,  and  S.  avenacca.  The  first  two  are  from  central 
and  southern  Europe,  the  third  from  Virginia.  The  first  species  is  selected  as 
the  type. 


160          BULLETIN  772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 

Podopogon  Raf.,  Neogenyt.  4.    1825.    Two  names  are  given,  "  Stipa  avenacea 
L.  and  "  barbatu  "  Michx.,  both  belonging  to  the  same  species. 


Fie.  93. — Porcupine  grass,  Stipa  spartea.    Plant,  X  1  ;  glumes  and  floret,  X  2. 


GENERA  OF   GRASSES  OF   THE   UNITED  STATES.  161 

Some  of  the  western  species  have  plumose  or  feathery  awns,  those 
of  Stipa  neo-mexicana  (Thurb.)  Scribn.  being  4  to  8  inches  long, 
plumose  to  the  second  bend,  those  of  the  handsome  S.  speciosa  Trin. 
and  Kupr.  plumose  below  the  single  bend.  A  striking  species  of  the 
upper  Mississippi  Valley  is  Stipa  spartea  Trin.  (fig.  93),  called 
porcupine  grass  and  devil's  darning  needles.  The  rigid  indurate 
fruiting  lemma  is  about  three-fourths  of  an  inch  long,  tapering  be- 
low into  a  very  sharp  hairy  point,  which  acts  like  a  barb,  and  termi- 
nating above  in  a  stout  awn  as  much  as  6  inches  long.  At  maturity 
the  awn  bends  twice  near  the  middle  and  becomes  tightly  twisted  be- 
low the  first  bend.  Variations  in  moisture  cause  the  awn  to  twist 
and  untwist,  by  which  movement  and  by  the  aid  of  the  sharp  callus 
it  can  penetrate  the  soil.  Several  other  species  have  elongate  awns, 
such  as  S.  avenacea  L.  of  the  eastern  half  of  the  United  States  and  S. 
comata  Trin.  and  Rupr.  of  the  western  half,  the  latter  species  being 
called  needle-and-thread  grass,  because  of  the  long  flexuous  upper 
portion  of  the  awns.  /Stipa  viridula  Trin.  and  its  allies  have  a  nar- 
row compact  panicle  and  comparatively  inconspicuous  awns  1  or  2 
inches  long.  One  of  these  species,  S.  vaseyi  Scribn.,  is  called  sleepy 
grass,  because  of  the  narcotic  effects  sometimes  produced  upon  horses 
when  they  have  fed  upon  it.  Sleepy  grass,  found  in  New  Mexico 
and  Colorado,  is  a  stout  grass  3  to  5  feet  high,  with  a  narrow  panicle 
as  much  as  a  foot  long,  the  sheaths  hairy  at  the  throat.  In  S.  tenuis- 
sima  Trin.  (fig.  94)  of  New  Mexico  the  fruit  is  very  small,  less  than 
3  mm.  long. 

The  species  of  Stipa  are  for  the  most  part  valuable  forage  plants. 
The  most  important  species  on  the  ranges  are  S.  viridula,  S.  minor 
(Vasey)  Scribn.,  and  &  lettermani  Vasey.  They  are  known  as  porcu- 
pine grasses.  All  have  narrow  panicles.  One  of  the  Old  World 
species,  S.  tenacissima  L.,  furnishes  a  part  of  the  esparto  or  alfa 
grass  of  Spain  and  Algeria  that  is  used  in  the  manufacture  of  paper 
and  cordage. 

77.  AEISTIDA  L.,  the  needle  grasses. 

Spikelets  1 -flowered,  the  rachilla  disarticulating  obliquely  above 
the  glumes;  glumes  equal  or  unequal,  narrow,  acute,  acuminate,  or 
awn-tipped ;  lemma  indurate,  narrow,  terete,  convolute,  with  a  hard, 
sharp-pointed,  usually  minutely  bearded  callus  at  base,  terminating 
above  in  a  usually  trifid  awn. 

Annual  or  perennial,  mostly  low  grasses,  with  narrow,  frequently 
convolute  blades  and  narrow  or  sometimes  open  panicles.  Species 
about  150,  in  the  warmer  regions  of  the  world;  36  species  in  the 
United  States ;  especially  abundant  in  the  Southwestern  States, 

97769°— 19— Bull.  772 11 


162          BULLETIN  772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  94.— Stipa  tenuissima.    Plant,  X  I ;  spikelet,  X  2 ;  glumes  and  floret,  X  5. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  163 

Type  species :  Aristida  adscensionis  L. 

Aristida  L.,  Sp.  PI.  82,  1753;  Gen.  PI.,  ed.  5,  35.  1754.  A  single  species  is 
described. 

Streptachne  R.  Br.,  Prodr.  Fl.  Nov.  Holl.  174.  1810.  A  single  species,  8. 
stipoides,  is  included.  In  this  the  lateral  awns  are  obsolete. 

Chaetaria  Beauv.,  Ess.  Agrost.  30,  pi.  8,  f.  5,  6.  1812.  Twenty-five  species 
are  listed,  two,  C.  stricta  (based  on  Ari-stida  stricta  Michx.)  and  C.  capillaris, 
are  illustrated.  Aristida  stricta  (fig.  5)  is  taken  as  the  type. 

Curtopogon  Beauv.,  Ess.  Agrost.  32,  159,  pi.  8,  f.  7.  1812.  The  only  species 
included  is  based  on  Aristida  dichotoma  L. 

Trixostis  Rat,  Bull.  Bot.  Seringe  1:  221.  1830.  A  single  species,  "Aristida, 
gracilis"  [Ell.],  is  included. 

Moulinsia  Raf.,  Bull.  Bot.  Seringe  1:  221.  1830.  A  single  species,  "Aristida 
lanosa  "  Muhl.,  is  included. 

Ortachne  Nees,  in  Seeman,  Bot.  Voy.  Herald  225.  1857.  A  single  species, 
based  on  Streptachne  pilosa  H.  B.  K.,  is  included. 

In  one  group  of  the  genus  the  lateral  awns  are  reduced  to  mere 
points  or  are  entirely  absent.     Two  species  of  this  group   (section 
Streptachne)  are  found  in  Arizona,  Aristida  scabra  (H.  B.  K.)  Kunth, 
with  a  curved  but  not  twisted  awn,  and  A. schiedeanaTr'm.  andRupr., 
with  a  twisted  awn.    The  former  is  found  also  in  southern  Florida. 
In  three  species  the  awn  is  articulate  at  base,  A.  desmantha  Trin. 
and  Rupr.,  with  short  neck,  A.  tuberculosa  Nutt.,  an  annual  with  a 
slender,  twisted  neck,  and  A.  calif omica  Thurb.,  a  perennial  with  a 
slender,  twisted  neck.    Aristida  dichotoma  Michx.,  a  small  annual 
with  a  coiled  central  awn,  is  common  in  the  Eastern  States.    Two 
other  annuals  are  common  in  the  eastern  part  of  our  country,  A.  gra- 
cilis  Ell.,  with  the  central  spreading  or  reflexed  awn  less  than  half 
an  inch  long,  and  A.  oligantha  Michx.  (fig.  95),  with  awns  2  or  3 
inches  long.     The  type  species,  A.  adscensionis  L.   (A.  bromoides 
H.  B.  K.),  has  a  wide  distribution  in  warm  countries  and  extends 
into  the  southwestern  United  States.    This  is  a  low  annual,  usually 
much  branched  at  base,  with  contracted  panicle,  the  first  glume  about 
half  as  long  as  the  second,  and  awns  about  one-third  of  an  inch  long. 
A  common  perennial  species  in  the  semiarid  regions  of  the  West  is 
A.  longiseta  Steud.,  called  dog-town  grass,  because  it  is  especially 
abundant  on  the  new  soil  of  prairie-dog  communities.    Aristida  fend- 
leriana  Steud.  is  an  allied  species  of  the  same  region.    The  first  has 
a  long  second  glume,  about  four-fifths  of  an  inch  long,  and  awns  as 
much  as  3  or  4  inches  long.    The  second  has  a  shorter  second  glume, 
about  three-fifths  of  an  inch  long,  and  awns  less  than  2  inches  long, 
and  grows  in  dense  tufts  with  curly  leaves  crowded  at  the  base  of 
the  plant.    Aristida  purpurea  Nutt.  differs  in  having  slender  curved 
pedicels.    These  species  are  troublesome  when  the  fruit  is  ripe,  be- 
cause this  with  its  spreading  awns  becomes  detached  at  maturity  and 
is  blown  about  by  the  wind.     These  fruits  are  sometimes  scattered 
in  vast  quantities,  the  wind  hurling  them  across  the  plains  with  the 
sharp-pointed  callus  in  advance.     They  work  their  way  into  the 
wool  of  sheep  and  into  the  nostrils  and  eyes  of  all  classes  of  stock. 


164  BULLETIN  772,  U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  95. — Needle  grass,  Aristida  oligantha.    Plant,  X  i  ;  glumes  and  floret,  X  2. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  165 

The  species  of  Aristida  are  of  distinctly  minor  importance  for  for- 
age except  in  the  Southwest,  where  several  species,  such  as  A.  longi- 
seta,  are  eaten  by  stock  before  the  flowers  are  produced.  The  annual 
species  of  the  Eastern  States  are  often  found  on  open  sterile  soil, 
and  hence  are  called  poverty  grass,  a  name  applied  also  to  annuals  of 
other  genera. 

6.  NAZIEAE,  THE  CURLY-MESQUITE  TRIBE. 

78.  NAZIA    Adans. 
(Tragus  Hall.) 

Spikelets  1 -flowered,  in  small  spikes  of  2  to  5,  the  spikes  sub- 
sessile,  falling  entire,  the  spikelets  sessile  on  a  very  short  zigzag  rachis, 
the  first  glumes  small,  thin,  or  wanting,  appressed  to  the  rachis,  the 
second  glumes  of  the  two  lower  spikelets  strongly  convex  with  3 
thick  nerves  bearing  a  row  of  squarrose,  stout  hooked  prickles  along 
each  side,  the  two  second  glumes  forming  the  halves  of  a  little  bur, 
the  upper  1  to  3  spikelets  reduced  and  sterile ;  lemmas  and  palea  thin, 
the  lemma  flat,  the  palea  strongly  convex. 

Low  annual  grasses,  with  flat  blades  and  terminal  inflorescence,  the 
burs  or  spikes  rather  closely  arranged  along  an  elongate,  slender  axis. 
Species  three,  in  the  tropical  regions  of  both  hemispheres ;  two  species 
being  introduced  in  the  southern  United  States. 

Type  species:  Cenchrus  racemosus  L. 

Nazia  Adans.,  Fam.  PI.  2:  581.  1763.  The  genus  is  based  on  Cenchrus 
racemosus  L. 

Trains  Hall.,  Stirp.  Helv.  2:  203.  1768.  Haller  cites  pre-Linnsean  authors 
who  connect  Tragus  with  Cenchrus  racemosus  L. 

Lappago  Schreb.,  Gen.  PI.  55.  1789.  A  new  name  is  proposed  for  Tragus 
Hall. 

Echisachys  Neck.,  Elem.  3:  228.  1790.  No  species  are  given.  The  author 
cites  "  Cenchrus  Lin.,"  but  his  description  shows  that  it  is  Linnseus's  first  species, 
Cenchrus  racemosus,  that  he  is  renaming. 

Nazia  racemosa  (L.)  Kuntze,  with  3  to  5  spikelets  in  each  cluster, 
the  lower  about  4  mm.  long,  is  found  in  open  ground  from  Texas  to 
Arizona,  and  N.  aliena  (Spreng.)  Scribn.  (fig.  96),  with  two  spike- 
lets  in  each  cluster,  the  lower  2  to  3  mm.  long,  here  and  there  through 
the  Southern  States  to  Arizona.  They  are  somewhat  weedy  grasses 
of  no  economic  importance. 

79.    OSTEBDAMIA   Neck. 

(Zoysia  Willd.) 

Spikelets  1 -flowered,  laterally  compressed,  appressed  flatwise 
against  the  slender  rachis,  glabrous,  disarticulating  below  the  glumes; 
first  glume  wanting;  second  glume  coriaceous,  mucronate,  or  short-, 
awned,  completely  infolding  the  thin  lemma  and  palea,  the  palea 
sometimes  obsolete* 


166          BULLETIN  772,  U.   S.   DEPARTMENT  OF  AGRICULTURE. 

Perennial  low  grasses  with  creeping  rhizomes,  short,  pungently 
pointed  blades,  and  terminal  spikelike  racemes,  the  spikelets  on  short 
appressed  pedicels.  Species  about  five,  southeastern  Asia  to  New 
Zealand. 

Type  species:  Agrostis  matrella  L. 

Osterdamia  Neck.,  Elem.  Bot.  3:  218.  1790.  In  a  note  appended  to  the  para- 
graph on  Agrostis,  Necker  states,  "Agrostis  matrella  Lin.  species  distincta, 
agrostidis  proxima,  quam  osterdamiam  appellamus,  char- 
actere  sequenti."  Although  Osterdamia,  Agrostis,  Milium,  and 
many  other  groups  are  called  by  Necker  species  of  his  genus 
Achyrophyton,  these  so-called  species  are  the  equivalent  of 
the  genera  of  his  contemporaries  and  are  usually  so  recog- 
nized by  botanical  writers. 

Zoysia  Willcl.,  Ges.  Naturf.  Freund.  Berlin,  Neue  Schrift.  3: 
440.     1801.     Type   and  only  species,   Z.   pun  (/ens   Willd. 

Matrella  Pers.,  Syn.  PI.  1:  73.    1805.    Type  species.  Affront!* 
juncca  Lam.,  the  only  species  described. 

Several  years  ago  a  species 
of  this  genus  was  introduced 
into  the  United  States  as  a 
lawn  grass  under  the  names 
Korean  lawn  grass  and  Jap- 
anese lawn  grass.  It  AT  as 
recommended  for  the  South- 
ern States  and  was  said  to  be 
hardy  as  far  north  as  Connecti- 
cut.1 The  species  then  intro- 


FIG.  96. — Nazia  aliena.     Plant,  X   I  ;  group  of  spikelets  (spike)  and  single  spikelet,   X  5. 

duced  appears  to  be  Osterdamia  japonica  (Steud.)  Hitchc.  (Zoysia 
japonica  Steud.).  Recently  a  fine-leaved  species,  Osterdamia  tenui- 
folia  (Willd.)  Kuntze,  has  been  introduced  into  Florida  and  has 
given  favorable  results.  The  original  species,  0.  matrella  (L.) 
Kuntze  (fig.  97),  manila  grass,  is  common  in  the  Philippine  Islands. 


1Scribner,  U.   S.  Dept.  Agr.,  Div.  Agrost.  Bull.  3:  95.      1896. 


GENERA  OF  GRASSES  OF  THE  UNITED  STATES.  167 

80.  HILAEIA  H.  B.  K. 

Spikelets  sessile,  in  groups  of  3,  the  groups  falling  from  the 
axis  entire,  the  central  spikelet  (next  the  axis)  fertile,  1-flowered,  the 
2  lateral  spikelets  staminate,  2-flowered ;  glumes  coriaceous,  those  of 
the  3  spikelets  forming  a  false  involucre,  in  some  species  connate 
at  the  base,  more  or  less  asymmetric,  usually  bearing  an  awn  on 


FIG.  97. — Manila  grass,  Osterdamia  matrella.     Plant,    X    I  ;  spikelet,    X   10 ;  floret  with 
caryopsis,  the  palea  obsolete,   X   10. 

one  side  from  about  the  middle;  lemma  and  palea  hyaline,  about 
equal  in  length. 

Perennial  low  grasses,  the  groups  of  spikelets  appressed  to  the 
axis,  in  terminal  spikes.  Species  five,  in  arid  regions,  southwestern 
United  States  to  Central  America,  all  but  one  found  within  the  limits 
of  the  United  States. 

Type  species:  Hilaria  cenchroides  H.  B.  K. 

Hilaria  H.  B.  K.,  Nov.  Gen.  and  Sp.  1 :  116.     1816.     Only  one  species  described. 


168  BULLETIN   772,   U.   S.  DEPARTMENT  OF  AGRICULTURE. 

Pleuraphis  Torr.,  Ann.  Lye.  N.  Y.  1:  148,  pi.  10.  1824.  Type  species  P. 
jamesii  Torr.,  the  only  one  described. 

Hexarrhena  Presl,  Rel.  Haenk.  1:  326,  pi.  45.  1830.  Type  species  H.  cen- 
chroides  Presl,  the  only  one  described.  This  is  the  same  as  Hilaria  cen- 
chroides. 


FIG.  98. — Curly  mesquite,  Hilaria  belangeri.  Plant,  X  1  ;  single  spike,  X  1 ;  group  of 
spikelets  seen  from  front  or  outside,  showing  staminate  spikelets  in  front  and  top  of 
fertile  spikelet  behind,  X  5  ;  same  group  from  behind  or  next  the  axis,  showing  the 
fertile  spikelet  in  front  and  the  two  staminate  spikelets  behind,  X  5  ;  fertile  spikelet 
as  seen  from  the  inside,  X  5  ;  fertile  floret,  X  5  ;  staminate  spikelet,  X  5. 

Schleropelta  Buckl.,  Prel.  Rep.  Geol.  and  Agr.  Surv.  Tex.  App.  1.  1866.  A 
single  species  is  included,  S.  stolonifera  Buckl.,  which  is  the  same  as  Hilaria 
lelangeri  Steud. 

Hilaria  belangeri  Steud.  (fig.  98)  is  a  common  grass  on  the  Great 
Plains  of  Texas  and  northern  Mexico.  In  Texas  it  is  called  curly 


GENERA  OF  GRASSES  OF  THE  UNITED  STATES.  169 

mesquite.  It  is  a  low  grass,  forming  wiry  stolons  that  in  favorable 
soil  produce  a  close,  firm  sod.  The  flowering  culms  are  a  few  inches 
high  and  terminate  in  a  short  spike.  Curly  mesquite  is  an  important 
grazing  grass  of  the  uplands  of  Texas.  Our  species  has  commonly 
been  referred  to  the  related,  H.  cenchroides^  of  Mexico. 

Hilaria  jamesii  (Torr.)  Benth.  (fig.  99),  an  erect  grass  about  a 
foot  high,  with  glumes  narrowed  above,  is  found  from  Wyoming  to 
Texas  and  southern  California.  This  is  called  galleta  grass  in  New 
Mexico.  HUaria  mutica  (Buckl.)  Benth.,  found  from  Texas  to  Ari- 
zona, differs  from  the  preceding  in  having  some  of  the  glumes  broad- 
ened above.  This  species  is  sometimes  called  tobosa  grass.  Hilaria 
rigida  (Thurb.)  Benth.,  with  felty  pubescent  branched  culms,  is 
found  from  Utah  to  southern  California.  This  also  is  called  galleta 
grass.  All  the  species  of  Hilaria  are  important  range  grasses.  The 
last  three  species,  with  scaly  rhizomes  instead  of  stolons  and  with 
glumes  bearing  an  awn  on  one  side,  compose  Pleuraphis,  held  by 
some  as  a  genus  distinct  from  Hilaria. 

81.  AEGOPOGON  Humb.  and  Bonpl. 

Spikelets  short-pedicellate,  in  groups  of  3,  the  group  short- 
pedunculate,  spreading,  the  peduncle  disarticulating  from  the  axis 
and  forming  a  pointed  stipe  below  the  group,  this  falling  entire; 
central  spikelet  shorter  pedicellate,  fertile,  the  2  lateral  ones  longer 
pedicellate  and  staminate  or  neuter;  glumes  membranaceous,  notched 
at  the  apex,  the  midnerve  extending  into  a  point  or  awn ;  lemma  and 
palea  thinner  than  the  glumes,  extending  beyond  them,  the  lemma 
3-nerved,  the  central  nerve  and  sometimes  also  the  lateral  ones  extend- 
ing into  awns,  the  palea  2-awned. 

Annual  low,  lax  grasses,  with  short,  narrow,  flat  blades  and  loose 
racemes  of  delicate  flower  clusters.  Species  three,  Arizona  to  Bolivia, 
one  within  the  United  States. 

Type  species :  Aegopogon  cenchroides  Humb.  and  Bonpl. 

Aegopogon  Humb.  and  Bonpl. ;  Willd.  Sp.  PI.  4 :  899.  1806.  Only  one  species 
is  described. 

Hymenothecium  Lag.,  Elench.  PI.  7.  1816.  In  the  Elenchus,  a  list  of  seeds, 
occurs  Hymenothecium  tenellum  Lag.  based  on  Cynosurus  tenellus  Cav.  The 
genus  was  published  as  new  by  Lagasca  in  Genera  et  Species  Plantarum,  a 
work  appearing  in  the  same  year  as  the  preceding  but  supposed  to  be  some- 
what later.  In  this  work  (p.  4)  four  species  are  given,  H.  unisetum,  H. 
tenellum,  H.  trisetum  (Cynosurus  gracilis  Cav.),  and  H.  quinquesetum.  Cy- 
nosurus tenellus  Cav.  is  accepted  as  the  type. 

Schellingia  Steud.,  Flora  33:  231,  pi.  1.  1850.  -Type,  8.  tenera  Steud.,  the 
only  species  described.  This  is  Aegopogon  cenchroides. 

The  only  species  in  the  United  States  is  Aegopogon  tenellus  (Cav.) 
Trin.  (fig.  100),  a  Mexican  species  extending  into  southern  Arizona. 
It  is  a  pretty  little  grass,  but  is  of  no  economic  importance. 


170          BULLETIN  7*72,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  99. — Galleta  grass,  Jlilaria  jamesii.     Plant,   X    \  ;  single  spike,    X   1 ;  two  views  of 

group  of  spikelets,  the  lower  a  dorsal  view,  the  upper  a  ventral  view,  X  5  ;  staminate 

spikelet     (below),     X     5;    fertile    spikelet    seen    from    the    inside    and  fertile    floret 
(above),  X  5. 


GENERA  OF   GRASSES   OF   THE   UNITED   STATES. 
7.  CHLORIDEAE,  THE   GRAMA  TRIBE. 

82.  LEPTOCHLOA  Beauv. 


171 


Spikelets  2  to  several  flowered,  sessile  or  short-pediceled,  approxi- 
mate or  somewhat  distant  along  one  side  of  a  slender  rachis,  the 
rachilla  disarticulating  above  the  glumes  and  between  the  florets; 
glumes  unequal  or  nearly  equal,  awnless  or  mucronate,  1-nerved, 


FIG.  100. — Aegopogon  tcnellus.     Plant,    X    I  ;  group  of  spikelets,    X    5  ;  lateral  spikelet, 
X   10 ;  central   (long-awned)   spikelet,    X    10. 

usually  shorter  than  the  first  lemma ;  lemmas  obtuse  or  acute,  some- 
times 2-toothed  and  mucronate  or  short-awned  from  between  the 
teeth,  3-nerved,  the  nerves  sometimes  pubescent. 

Annual  or  perennial  grasses,  with  flat  blades  and  numerous  spikes 
or  racemes  scattered  along  a  common  axis  forming  a  long  or  some- 


172  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

times  short  panicle.  Species  probably  20,  in  the  warmer  regions; 
10  species  in  the  United  States,  mostly  in  the  Southern  and  South- 
western States. 

Type  species:  Cynosnrus  virgatus  L. 

Leptochloa  Beauv.,  Ess.  Agrost.  71,  166,  pi.  15,  f.  1.  1812.  Beauvois  includes 
three  species,  Cynosnrus  capiltoceus,  Eleusine  flliformis,  and  E.  virgata,  all  of 
which  appear  in  the  index  under  Leptochloa.  The  third  species  is  figured  and 
hence  is  selected  as  the  type. 

Diplachne  Beauv.,  Ess.  Agrost.  80,  pi.  16,  f.  9.  1812.  The  type  is  Festuca 
fascicularis  Lam.,  the  only  species  mentioned.  This  is  figured  by  Beauvois. 

Rabdochloa  Beauv.,  Ess.  Agrost.  84,  pi.  17,  f.  3.  1812.  Beauvois  includes 
Cynosurus  monostachyos,  C.  I'irgatus,  C.  domingensis,  C.  cruciatus,  and  C. 
mucronatus,  the  last  two  with  question.  The  species  figured,  C.  domingensis, 
in  the  explanation  to  the  plates  called  Rabdochloa  domingensis,  is  selected  as 
the  type. 

Oxydenia  Nutt.,  Gen,  PI.  1:  76.  1818.  Only  one  species  included,  O.  at- 
tenuata,  which  is  Leptochloa  filiformis. 

Some  authors  *  recognize  Diplachne  as  a  distinct  genus,  including  Leptochloa 
fascicularis,  L.  floribunda,  and  L.  dubia.  In  this  group  the  spikelets  are  some- 
what pediceled  and  are  less  distinctly  arranged  in  one-sided  spikes.  Those 
who  recognize  the  genus  place  it  in  the  tribe  Festuceae. 

Leptochloa  filiformis  (Lam.)  Beauv.  (fig.  101)  is  an  annual  with 
papillate-pilose  sheaths,  small  spikelets,  the  awnless  florets  shorter 
than  the  glumes,  and  numerous  very  slender  spikes  3  to  6  inches  long 
arranged  in  a  panicle  as  much  as  a  foot  long.  This  is  a  weed  in 
cultivated  soil  from  Virginia  to  Florida  and  California;  common 
also  in  the  Tropics;  sometimes  called  red  sprangle-top. 

Leptochloa  fascicularis  (Lam.)  Gray  is  a  smooth,  erect  or  pros- 
trate annual  with  several-flowered  spikelets,  the  awned  florets  longer 
than  the  glumes;  found  in  ditches  and  brackish  meadows  from 
Massachusetts  to  Florida  and  New  Mexico. 

The  other  species  are  more  local.  Two  perennials,  L.  domingensis 
(Jacq.)  Trin.  and  L.  virgata  (L.)  Beauv.,  are  tropical  species  which 
reach  the  United  States  in  southern  Florida  and  southern  Texas, 
respectively.  Leptochloa  dubia  (H.  B.  K.)  Nees,  a  perennial  with 
comparatively  few  spikes  and  broad  lemmas  notched  at  the  apex,  the 
nerves  glabrous  (the  margin  pubescent),  is  found  in  Florida  and 
from  Texas  to  New  Mexico.  In  the  Southwest  it  is  called  sprangle 
or  sprangle-top  and  Texas  crowfoot,  and  it  is  important  as  a  forage 
grass. 

For  a  revision  of  the  species  of  Leptochloa  found  in  the  United 
States,  see  Hitchcock,  U.  S.  Dept.  Agr.,  Bur.  PL  Ind.  Bull.  33.  1903. 

S3.  TRIPOGOX  Roth. 

Spikelets  several-flowered,  nearly  sessile,  and  appressed  in  two  rows 
along  one  side  of  a  slender  rachis,  the  rachilla  disarticulating  above 
the  glumes  and  bet\veen  the  florets;  glumes  somewhat  unequal, 
acute  or  acuminate,  narrow,  1 -nerved;  lemmas  narrow.  3-nerved, 

1  Nash  in  Small,  Fl.  Southeast.  U.  S.  145,  1900  ;  in  Britt.  and  Brown,  Illustr.  FL,  ed.  2, 
1:236.  1913. 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES  173 


FIG.  101. — Red  sprangle-top,  Leptochloa  filiformis.    Plant,   X   i  ;  spikelet  and  floret,  X 10. 


174          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

bearing  at  the  base  a  tuft  of  long  hairs,  bifid  at  the  apex,  the  mid- 
nerve  extending  as  a  short  awn. 

Our  species  is  a  low,  tufted  perennial,  with  capillary  blades  and 
slender  solitary  spikes,  the  spikelets  somewhat  distant.  Species  about 
nine,  East  Indian  and  African  except  one  American. 

Type  species:  Tripogon  bromoifles  Roth. 
Tripogon  Roth;  Roem.  and  Schult,  Syst.  Veg.  2: 
600.    1817.    Only  one  species  described. 

The  American   species,   Tripogon  spica- 
tus     (Xees)     Ekman     (Leptochloa    spicata 
Scribn.)    (fig.  102),  is  found  on  sterile  hills 
in  Texas  and  northern  Mexico,  Cuba, 
and  South  America.    It  is  of  no  im- 
portance agriculturally. 

84.    ELEUSINE  Gaertn. 

Spikelets  few  to  several  flowered, 
compressed,  sessile  and  closely  im- 
bricate, in  two  rows  along  one  side 
of  a  rather  broad  rachis,  the  latter 
not  prolonged  beyond  the  spikelets; 
rachilla  disarticulating  above  the 


FIG.  102. — Tripogon  spicatus.     Plant,   x   i  ;  spikelet  and  floret,   X   5. 

glumes  and  between  the  florets,  glumes  unequal,  rather  broad,  acute3 
1-nerved,  shorter  than  the  first  lemma ;  lemmas  acute,  with  3  strong 
green  nerves  close  together  forming  a  keel,  the  uppermost  somewhat 
reduced ;  seed  dark  brown,  roughened  by  fine  ridges,  loosely  inclosed 
in  the  thin  pericarp. 

Annual  grasses,  with  two  to  several  rather  stout  spikes,  digitate 
at  the  summit  of  the  culms,  sometimes  with  one  or  two  a  short  dis- 


GENERA  OF  GRASSES   OF  THE   UNITED  STATES.  175 

tance  below,  or  rarely  with  a  single  terminal  spike.  Species  about 
six,  in  the  warm  regions  of  the  Eastern  Hemisphere,  one  a  common 
introduced  weed  in  America. 

Type  species:  EJeusine  coracana  Gnertn. 

Eieusine  Gaertn.,  Fruct.  and  Sem.  1 :  7,  pi.  1,  f.  11.  1788.  Two  species  are 
described,  E.  coracana  and  E.  indica.  The  first,  being  figured,  is  selected  as  the 
type. 

Eleusine  indica  (L.)  Gaertn.  (fig.  103)  is  a  common  garden  and 
roadside  weed  throughout  the  warmer  parts  of  America,  extending 
northward  to  Illinois  and  Massachusetts.  It  is  usually  spreading  or 
prostrate,  with  two  to  several  spikes,  or  rarely  one.  This  species  is 
sometimes  called  goose-grass  and  yard-grass. 

The  type  species  of  the  genus,  Eieusine  coracana  Gaertn.,  is  culti- 
vated in  the  Tropics  of  the  Old  World  for  the  seed,  which  is  used  for 
human  food  by  the  poor  or  primitive  people.  It  differs  from 
E.  indica  in  its  larger  size,  stouter,  often  incurved  spikes,  and  globose 
seed. 

85.  DACTYLOCTENITJM  Willcl. 

Spikelets  3  to  5  flowered,  compressed,  sessile  and  closely  imbricate, 
in  two  rows  along  one  side  of  the  rather  narrow  flat  rachis,  the  end 
projecting  in  a  point  beyond  the  spikelets;  rachilla  disarticulating 
above  the  first  glume  and  between  the  florets;  glumes  somewhat  un- 
equal, broad,  1-nerved,  the  first  persistent  upon  the  rachis,  the  second 
mucronate  or  short-awned  below  the  tip,  deciduous;  lemmas  firm, 
broad,  keeled,  acuminate  or  short-awned,  3-nerved,  the  lateral  nerves 
indistinct,  the  upper  floret  reduced;  the  palea  about  as  long  as  the 
lemma ;  seed  subglobose,  ridged  or  wrinkled,  inclosed  in  a  thin,  early- 
disappearing  pericarp. 

Annual  or  perennial  grasses,  with  flat  blades  and  two  to  several 
short  thick  spikes,  digitate  and  widely  spreading  at  the  summit  of 
the  culms.  Species  three,  in  the  warmer  parts  of  the  Eastern  Hemi- 
sphere, one  a  common  weed  in  tropical  America. 

Type  species:  Cynosurus  aegyptius  L. 

Dactyloctenium  Willd.,  Enum.  PI.  1029.  1809.  Willdenow  describes  but  one 
species,  D.  aegyptiacum,  based  on  Cynosurm  aegyptius  L. 

Our  only  species  is  Dactyloctenium  aegyptium  (L.)  Richt. 
(D.  aegyptiacum  Willd.)  (fig.  104),  a  tropical  weed  which  extends 
northward  to  New  York  and  Illinois.  It  is  a  prostrate  annual  with 
2  to  5  spikes,  often  forming  mats  rooting  at  the  nodes.  Sometimes 
called  crowfoot  grass. 

86.  CAPRIOLA  Adans. 
(Cynodon  Rich.) 

Spikelets  1 -flowered,  awnless,  sessile  in  two  rows  along  one  side  of 
a  slender  continuous  rachis,  the  rachilla  disarticulating  above  the 
glumes  and  prolonged  behind  the  palea  as  a  slender  naked  bristle, 


176  BULLETIN   772,   U.   S.   DEPARTMENT   OF   AGRICULTURE, 


Tic.  103. — Goose-grass,  Eleusine  indica.     Plant,   X   i  ;  spikelet,  floret,  and  seed   (without 

pericarp),   X   5. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES. 


177 


this  sometimes  bearing  a  rudimentary  lemma ;  glumes  narrow,  acumi- 
nate, 1-nerved,  about  equal,  shorter  than  the  floret;  lemma  strongly 


FIG.    104. — Crowfoot   grass,    Dactyloctenium   aegyptium.      Plant,    X    i  ;    spikelet,    floret, 
and  seed   (without  pericarp),    X   5. 

compressed,  pubescent  on  the  keel,  firm  in  texture,  3-nerved,  the 
lateral  nerves  close  to  the  margins. 
97769 °— 19— Bull.  772 12 


178  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

Perennial,  usually  low  grasses,  with  creeping  stolons  or  rhizomes, 
short  blades,  and  several  slender  spikes  digitate  at  the  summit  of 
the  upright  flowering  stems.  Species  six,  of  which  three  are  Aus- 
tralian, one  species  widely  dis- 
tributed in  the  warmer  regions 
of  the  globe. 

Type  species:  Panicum  dacty- 
lon  L. 

Capriola  Adans.,  Fam.  PI.  2:  31, 
532.  1763.  The  genera  are  indi- 
cated and  distinguished  by  Aclanson 
in  a  much  abbreviated  and  often  un- 
satisfactory manner.  The  tabular 
arrangement  of  the  genera  of  Phal- 
arides,  his  first  section  of  the  grass 
family  or  Gramina,  includes  Cap- 


FIG.   105. — Bermuda  grass,  Capriola  dactylon.     Plant, 

floret,   X   5. 


X    2  ;  spikelet  and  two  views  of 


riola,  with  the  following  diagnosis,  interpreting  the  table :  Summit  of  leaf  sheath 
hairy  ;  flowers  in  digitate  spikes ;  glumes  laterally  compressed  ;  lemma  awn  less. 
In  the  index  there  is  given  as  a  synonym  under  Capriola,  "  Gramen  dactylon 
Offic."  The  last  phrase  appears  in  the  first  edition  of  the  Species  Plantarum  1 
in  the  synonymy  under  Panicum  dactylon  as  "  Gramen  dactylon,  radice  repente. 
s.  officinarum.  Scheuch.  gram.  104,"  thus  connecting  Capriola  Adans.  with 
Panicum  dactylon. 

Cynodon  Rich. ;  Pers.,  Syn.  PI.  1:  85.    1805.    Only  one  species  described,  C.  dac- 
tylon, based  on  Panicum  dactylon  L. 

The  only  species  in  Xofth  America  is  Capriola  dactylon   (L.) 
Kuntze  (fig.  105),  commonly  known  as  Bermuda  grass.     This  is  a 


.,  Sp.  PL  58.     1753. 


GENERA  OF   GRASSES   OF   THE   UNITED   STATES.  179 

native  of  the  Mediterranean  region,  but  is  common  in  the  southern 
United  States,  extending  north  to  Maryland,  southern  Kansas,  and 
the  interior  valleys  of  California. 

Bermuda  grass  is  the  most  important  pasture  grass  of  the  South- 
ern States,  and  is  also  widely  utilized  there  as  a  lawn  grass.  On 
alluvial  ground  it  may  grow  sufficiently  rank  to  be  cut  for  hay.  It 
propagates  readily  by  its  rhizomes  and  stolons  and  on  this  account 
may  become  a  pestiferous  weed  in  cultivated  fields.  This  grass  is 
known  also  as  wire-grass  (especially  the  weedy  form  in  fields),  Ba- 
hama grass  in  the  West  Indies,  and  manienie  in  the  Hawaiian 
Islands. 

A.  larger  form,  Capriola  dactylon  maritima  (H.  B.  K.)  Hitchc. 
(Cynodon  maritimus  H.  B.  K.),  is  found  along  the  seacoast  of 

Florida. 

87.  WILI/KOMMIA  Hack. 

Spikelets  1-flowered,  dorsally  compressed,  sessile  in  two  rows  on 
one  side  of  a  slender  rachis  and  appressed  to  it,  the  rachilla  some- 
what lengthened  below  and  above  the  second  glume,  disarticulating 
just  above  it,  not  prolonged  above  the  floret;  glumes  thin,  the  first 
narrow,  about  two-thirds  as  long  as  the  second,  nerveless,  obtuse, 
the  second  1-nerved,  subacute;  lemma  about  as  long  as  the  second 
glume,  awnless,  3-nerved,  the  lateral  nerves  near  the  margin,  the 
back  of  the  lemma  sparingly  pubescent  between  the  nerves,  the  mar- 
gins densely  covered  with  silky  hairs;  palea  2-nerved,  the  nerves 
densely  silky  hairy. 

Annuals  or  perennials,  with  several  short  spikes  scattered  along  a 
main  axis;  our  species,  a  low,  tufted  perennial.  Species  four;  three 
in  South  Africa,  one  in  Texas. 

Type  species:  Willkommia  sarmcntosa  Hack. 

Willkommia  Hack.,  Verh.  Bot.  Ver.  Brandenburg  30:  145.  1888.  Hackel  de- 
scribes two  species,  W.  sarmentosa,  a  perennial,  and  W.  annua,  ,an  annual,  both 
from  German  Southwest  Africa.  The  first  species  is  selected  as  the  type. 

Willkommia  texana  Hitchc.  (fig.  106),  confined  to  a  few  localities 
in  Texas,  in  alkali  spots  in  prairies  and  openings  in  woods,  has  no 
agricultural  importance. 

88.    SCHEDONNARDUS    StCUd. 

Spikelets  1-flowered,  sessile  and  somewhat  distant  in  two  rows  on 
one  side  of  a  slender,  continuous  3-angled  rachis,  appressed  to  its 
slightly  concave  sides,  the  rachilla  disarticulating  above  the  glumes, 
not  prolonged;  glumes  narrow,  stiff,  somewhat  unequal,  acuminate, 
1-nerved ;  lemmas  narrow,  acuminate,  a  little  longer  than  the  glumes, 
3-nerved. 

A  low,  tufted  perennial,  with  stiff,  slender,  divergent  spikes  ar- 
ranged rather  remotely  along  a  common  axis.  Species  one,  on  the 
Great  Plains  of  the  United  States  and  in  Argentina. 


180  BULLETIN    772,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 


Type  species :  Schedonnardus  texanus  Steud. 

Schedonnardus  Steud.,  Syn.  PI.  Glum.  1:146.     1854.     A  single  species  de- 
scribed, S.  texanus,  based  on  Drumiuond's  no.  360  from  Texas.     This  is  /S. 

paniculatus  (Nutt.)  Trel.  (Lcp- 
turns  paniculatus  Nutt.). 

Spirochloe  Lunell,  Amer. 
Midi.  Nat.  4:  220.  1915.  Pro- 
posed for  "  Schedonnardus 
Steud  ...  not  thought  per- 
missible, being  built  on 
Nardus." 

Schedonnardus  panicu- 
latus (fig.  10T),  the  only 
species  of  the  genus,  is 
found  on  prairies  and 
plains  from  Montana  and 
Illinois  to  Texas.  The  axis 
of  the  inflorescence  elon- 
gates after  flowering,  be- 
coming 1  to  2  feet  long, 
curved  in  a  loose  spiral. 
The  whole  breaks  away  at 
maturity  and  rolls  before 
the  wind  as  a  tumbleweed. 
The  species  is  a  forage 
grass,  but  the  plants  are 
low  and  in  the  main  form 
only  an  inconsiderable  pro- 
portion of  the  total  forage. 

89.  BECKMANNIA  Host. 

Spikelets  1-flowered, 
rarely  2-flowered,  laterally 
compressed,  subcircular, 
nearly  sessile  and  closely 
imbricate,  in  two  rows 
along  one  side  of  a  slender 
continuous  rachis,  disartic- 
ulating below  the  glumes, 


FIG.  106. — Willkommia  texana. 


Plant,    X    I  ;   two  views  of  spikelet  and  two  views  of 
floret,    X   5. 


GENERA  OF   GRASSES  OF   THE   UNITED  STATES.  181 

falling  entire;   glumes  equal,  inflated,  obovate.  3-nerved,  rounded 
above  but  the  apex  apiculate;  lemma  narrow,  5-nerved,  acuminate, 


about  as  long  as  the 
glumes;  palea  2- 
nerved,  nearly  as 
long  as  the  lemma. 
Aa  erect,  rather 
stout  annual,  with 
flat  blades  and  nu- 
merous short  ap- 
pressed  spikes  in  a 
narrow  more  or  less 
interrupted  panicle. 
Species  one,  in  the 
cooler  parts  of 
America  and  Eur- 
asia. 

Type  species :  PJialaris  erucae- 
fonnis  L. 

Beckmannia  Host,  Gram. 
Austr.  3:  5,  pi.  6.  1805.  Only 
one  species  described. 

Beckmannia  erueaeformis 
(L.)  Host  (fig.  108)  is  a 
marsh  plant,  found  from 
Iowa  to  California  and 
Alaska  where  it  is  often 
called  slough-grass.  It  is 

FIG.    107.— Schedonnardus    t> aniculatus.    palatable    to    Stock,    is 
Plant,   X   I  ;  spikelet  and  floret,   X   5.        r 


182  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


times  sufficiently  abundant  locally  to  be  an  important  forage 
grass,  and  is  not  infrequently  used  for  hay.  The  European 
form  has  2-flowered 
spikelets. 

90.  SPARTINA  Schreb. 

Spikelets  1-flow- 
ered,  much  flattened 
laterally,  sessile  and 
usually  closely  im- 
bricate, on  one  side 
of  a  continuous  ra- 
chis,  disarticulating 
below  the  glumes, 
the  rachilla  not  pro- 
duced beyond  the 
floret;  glumes 
keeled,  l-nerved5 


FIG.    108. — Slough-grass,   Beckmannia   erucaeformis. 

X   5. 


Plant,    X 


spikelet  and   floret, 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  183 

acute  or  short-awned,  the  first  shorter,  the  second  often  ex- 
ceeding the  lemma;  lemma  firm,  keeled,  the  lateral  nerves  obscure, 
narrowed  to  a  rather  obtuse  point;  palea  2-nerved,  keeled  and  flat- 
tened, the  keel  between  or  at  one  side  of  the  nerves. 

Stout,  erect,  often  tall  perennials,  with  usually  extensively  creep- 
ing, firm,  scaly  rhizomes,  long  tough  blades,  and  two  to  many  ap- 
pressed  or  sometimes  spreading  spikes  racemose  on  the  main  axis. 
Species  about  14,  all  North  American  except  two  or  three  along  the 
coast  of  Europe,  Africa,  and  South  America. 

Type  species:  Spartina  schreberi  Gmel, 

Spartina  Schreb. ;  Ginel.,  S-yst.  Nat.  ed.  13.  2 :  123.  1791.  The  genus  was  first 
described  by  Schreber  in  his  Genera  Plantarum,1  but  no  species  was  mentioned. 
Ginelin  merely  assigns  a  specific  name  to  the  description  given  by  Schreber. 
Spartina  schreberi  is  not  recognized  by  European  botanists,  but  it  doubt- 
less is  the  common  European  species,  S.  maritima  (Curt.)  Fernald  (S.  stricta 
Roth). 

Trachynotia  Michx.,  Fl.  Bor.  Amer.  1:  63.  1803.  Type  species  T.  cyno- 
suroides. Michaux  describes  three  species,  T.  cynosuroides,  T.  polystachya,  and 
T.  juncea.  The  first  species  described  is  what  is  now  called  Spartina  michauxi- 
ana  Hitchc.,  but  the  synonym,  Dactylis  cynosuroides  L.,  from  which  the  specific 
name  is  taken,  shows  that  Michaux  had  misapplied  the  name.  The  second  spe- 
cies, T.  polystachya,  is  Dactylis  cynosuroides  L.,  now  called  Spartina  cynosu- 
roides (L.)  Roth.  Michaux  remarks  that  this  may  be  only  a  variety  of  the  first 
species.  It  appears  then  that  to  Michaux  the  first  species  typifies  the  genus, 
and  hence  is  selected  here  as  the  type  species. 

Limnetis  Pers.,  Syn.  PI.  1 :  72.  1805.  Four  species  are  described,  L.  pungens, 
L.  juncea,  L.  cynosuroides,  and  L.  polystachya.  The  first  species,  which  is  the 
same  as  Spartina  maritima,  is  selected  as  the  type,  as  that  is  a  native  of  Europe 
and  is  indigenous  from  the  standpoint  of  the  author.  The  other  three  species 
are  American. 

There  are  eight  species  in  the  United  States.  All  but  two  are  found 
on  or  near  the  coast.  Spartina  cynosuroides  (L.)  Roth,  a  stout  grass 
as  much  as  9  feet  tall,  is  found  along  the  Atlantic  coast.  The  com- 
monest coastal  species  is  S.  patens  (Ait.)  Muhl.  (including  S.  juncea 
Michx.) ,  which  covers  vast  areas  of  salt  marsh  from  Newfoundland  to 
Texas.  This  is  a  slender  wiry  species  usually  less  than  3  feet  tall,  with 
only  a  few  somewhat  spreading  spikes.  Spartina  alterniftora  Loisel. 
and  its  two  varieties,  glabra  (Muhl.)  Fern,  and  pilosa  (Merr.)  Fern., 
also  of  the  Atlantic  coast,  have  stout  stems  and  closely  appressed 
spikes,  forming  a  cylindric  inflorescence.  A  somewhat  local  species, 
S.  sp.irtinae  (Trin.)  Merr.,  is  found  on  the  Texas  coast.  Another 
local  species,  S.  foliosa  Trin.,  is  found  on  the  coast  of  California.  The 
only  species  without  well-marked  rhizomes  is  S.  ~ba~keri  Merr.,  of  the 
f  resh- water  marshes  and  low  savannas  of  Florida  and  coastal  Georgia. 
Two  species  are  found  in  the  interior  of  the  United  States.  One,  &. 
michauxiana  Hitchc.  (fig.  109),  is  common  in  marshes  and  sloughs 
from  New  England  to  the  Great  Plains.  A  second,  S.  gradlis  Trin.,  is 
found  in  alkaline  grassland  in  the  Western  States.  The  first  of  these 
is  used  for  thatching  sheds  and  covering  hay  stacks.  The  leaves  of 

1  Schreb.  Gen.  PI.  1:  43.     1789. 


184          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE, 


FIG.  109.- — Marsh-grass,  Spartina  michauxiana.     Plant,   X    \  ;  spikelet  and  floret,    X   5. 


GENERA  OF  GRASSES   OF  THE  UNITED  STATES.  185 

S.  bakeri  and  S.  patens  jimcea  (Michx.)  Hitchc.  are  used  for  making 
brooms.  The  marsh  hay  of  the  Atlantic  coast,  much  used  for  bedding 
and  packing,  often  consists  largely  of  JS.  patens.  The  species  of 
Spartina  are  too  coarse  for  forage. 

For  a  revision  of  the  species  found  in  the  United  States,  see  Mer- 
rill, U.  S.  Dept.  Agr.,  Bur.  PL  Ind.  Bull.  9.  1912. 

91.  CAMPULOSUS  Desv. 
(Ctenium  Panzer.) 

Spikelets  several-flowered  but  with  only  one  perfect  floret,  sessile 
and  closely  imbricate,  on  one  side  of  a  continuous  rachis,  the  rachilla 
disarticulating  above  the  glumes;  glumes  unequal,  the  first  small, 
hyaline,  1-nerved,  the  second  as  long  as  the  lemmas,  firm,  3  to  4 
nerved,  bearing  on  the  back  a  strong  divergent  awn ;  lemmas  rather 
papery,  3-nerved,  villous  on  the  lateral  nerves  and  on  the  callus, 
bearing  a  short  straight  awn  on  the  back  just  below  the  apex,  the  first 
and  second  lemmas  empty,  the  third  inclosing  a  perfect  flower,  the 
upper  1  to  3  empty  and  successively  smaller. 

Erect,  slender,  rather  tall  perennials,  with  usually  solitary,  often 
curved  spikes.  Species  about  12,  in  the  warm  regions,  three  being 
in  the  Eastern  Hemisphere  and  the  rest  in  America ;  two  species  are 
found  in  the  southeastern  United  States. 

Type  species:  Chloris  monostachya  Michx. 

Campulosus  Desv.,  Nouv.  Bull.  Soc.  Philom.  Paris  2 :  189.  1810.  Two  species 
are  mentioned,  C.  gracilior  Desv.  (based  on  Chloris  monostachya  Michx.,  which 
is  Campulosus  aroma ticus ),  and  C.  hirsulus  Desv.  (based  on  Chloris  falcata 
Swartz).  The  first  is  selected  as  the  type.  The  second  is  now  referred  to 
Harpechloa. 

Ctenium  Panzer,  Denkschr.  Baier.  Akad.  Wiss.  Miinchen  4 :  288,  pi.  13.  1813. 
(Ideeli  Gatt.  Graser,  38.)  Only  one  species  is  described,  Chloris  monostachya 
Michx.,  to  which  Panzer  gives  the  name  Ctenium  carolinianum. 

Monocera  Ell.,  Bot.  S.  C.  and  Ga.  1:  176.  1816.  A  single  species,  based  on 
Aeoilops  aromaticum  Walt.,  is  included. 

Monathera  Raf.,  Amer.  Month.  Mag.  4:  190.  1819.  "Monocera  Elliott  .  .  . 
must  be  changed,  because  there  is  already  a  genus  of  shell  of  the  same  name." 

Our  two  species  are  confined  to  the  Southeastern  States,  one  of 
them,  Campulosus  floridanm  Hitchc.,  to  Florida,  the  other,  C.  aro- 
maticus  (Walt.)  Trin.  (fig.  110),  called  toothache  grass,  extending 
from  North  Carolina  along  the  Coastal  Plain  to  Louisiana.  Both 
species  are  rather  infrequent  and  neither  is  of  importance  agri- 
culturally. 

92.  GYMNOPOGON  Beauv. 

Spikelets  1  or  rarely  2  or  3  flowered,  nearly  sessile,  appressed  and 
usually  remote  in  two  rows  along  one  side  of  a  slender  continuous 
rachis,  the  rachilla  disarticulating  above  the  glumes  and  prolonged 
behind  the  one  or  more  fertile  florets  as  a  slender  stipe,  bearing  a 
rudiment  of  a  floret,  this  sometimes  with  one  or  two  slender  awns ; 


186  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

glumes  narrow,  acuminate,  1 -nerved,  usually  longer  than  the  floret; 
lemmas  narrow,  3-nerved,  the  lateral  nerves  near  the  margin,  the 


FIG.  110. — Toothache  grass,   Campulosus  aromaticus.     Plant,    X    \  ',  splkelet  and  fertile 

floret  (palea  side  up),   X   5. 

apex  minutely  bifid,  bearing  between  the  teeth  a  slender  awn,  or 
rarely  awnless. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  187 

Perennial  or  rarely  annual  grasses,  with  short,  flat,  stiff  blades, 
numerous  stiff,  slender,  divergent  spikes  loosely  scattered  along  the 
upper  part  of  the  culm,  or  sometimes  aggregate  toward  the  summit, 
the  spikes  often  deflexed  at  maturity.  Species  10,  nearly  all  Amer- 
ican ;  3  species  in  the  southeastern  United  States. 

Type  species :  Andropogon  ambiguus  Michx. 

Gymnopogon  Beauv.,  Ess.  Agrost.  41,  pi.  9,  f.  3.  1812.  Beauvois  mentions  one 
species,  Andropogon  ambiguus  Michx.,  which  is  figured.  In  the  description  of 
the  plate  the  name  given  is  Gymnopogon,  raceinosus. 

Alloiatheros  Ell.,  Bot.  S.  C.  and  Ga.  1:  146.  1816.  This  name  is  casually 
mentioned  by  Elliott  in  the  description  of  Andropogon  ambiguus:  "I  once  in- 
tended to  insert  it  as  a  distinct  genus  under  the  name  of  Alloiatheros,  from  the 
dissimilarity  of  its  awns,  not  only  in  position  but  in  figure." 

Anthopogon  Nutt,  Gen.  PI.  1:  81.  1818.  Based  on  Andropogon  ambiguus 
Michx.,  which  name  Nuttall  changes  to  Anthopogon  lepturoides. 

The  spikelets  are  usually  1-flowered  and  awned,but  in  G-ymnopogon 
chapmanianus  Hitchc.,  of  Florida,  they  are  2  to  4  flowered  and  awn- 
less.  This  species  shows  in  its  spikelet  characters  a  transition  to 
Leptochloa,  but  in  habit  it  closely  resembles  the  other  two  species  of 
the  United  States.  In  G.  foliosm  (Willd.)  Nees,  of  Porto  Eico  and 
South  America,  the  rudiment  bears  two  long  awns.  Our  species  are 
perennials,  with  an  inflorescence  of  scattered  spikes. 

Our  commonest  species  is  Gymnopogon  ambiguus  (Michx.)  B.  S.  P. 
(fig.  Ill) ,  found  in  sandy  soil  from  New  Jersey  to  Missouri  and  south 
to  Florida  and  Texas.  Another  species,  G.  l>revifolius  Trin.,  grows 
from  New  Jersey  to  Florida.  This  species  differs  from  the  preced- 
ing in  having  the  rachis  spikelet  bearing  only  along  the  upper  half . 
The  species  have  no  agricultural  importance. 

93.  CHLOBIS  Swartz. 

Spikelets  with  1  perfect  floret,  sessile,  in  two  rows  along  one 
side  of  a  continuous  rachis,  the  rachilla  disarticulating  above  the 
glumes,  produced  beyond  the  perfect  floret  and  bearing  1  to  several 
reduced  florets  consisting  of  empty  lemmas,  these  often  truncate,  and, 
if  more  than  one,  the  smaller  ones  inclosed  in  the  lower,  forming  a 
usually  club-shaped  rudiment;  glumes  somewhat  unequal,  the  first 
shorter,  narrow,  acute;  lemma  keeled,  usually  broad,  1  to  5  nerved, 
often  villous  on  the  callus  and  villous  or  long-ciliate  on  the  keel  or 
marginal  nerves,  awned  from  between  the  short  teeth  of  a  bifid  apex, 
the  awn  slender  or  sometimes  reduced  to  a  mucro,  the  sterile  lemmas 
awned  or  awnless. 

Perennial  or  sometimes  annual,  tufted  grasses,  with  flat  blades  and 
two  to  several  often  showy  and  feathery  spikes  aggregate  at  the 
summit  of  the  culms.  Species  about  60,  in  the  warmer  regions ;  15  in 
the  southern  United  States. 

Type  species :  Agrostis  cruciata  L. 

Chloris  Swartz,  Prod.  Veg.  Ind.  Occ.  25.  1788.  Swartz  describes  five  species, 
C,  cruciata,  C.  ciliata,  C.  petraea,  C.  polydactyla,  and  C.  radiata,  all  from  the 


188          BULLETIN   772,   U.   S.   DEPARTMENT  OP  AGRICULTURE. 


FIG.  111.- — Gymnopogon  ambigitus.     Plant,   X   \  ',  spikelet  and  floret,   X   5. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  189 

West  Indies.  The  second  and  third  are  described  as  new ;  the  others  are  based 
on  Linnsean  species,  the  first  on  Agrostis  cruciata,  the  fourth  "on  Andropogon 
polydactylon,  and  the  fifth  on  Agrostis  radiata.  The  first  species  is  selected  as 
the  type. 

Eustachys  Desv.,  Nouv.  Bull.  Soc.  Philom.  Paris  2:  188.  1810.  One  species 
is  described,  E.  petraeus,  based  oil  Chloris  petraea  Swartz.  Eustachys,  recog- 
nized by  some  American  botanists  as  distinct,  forms  a  section  of  the  genus 
Chloris  and  includes  four  species,  C.  petraea,  C.  glauca  (Chapm.)  Vasey,  C. 
floridana  (Chapm.)  Vasey,  and  C.  neglecta  Nash.  The  group  differs  from 
Euchloris  in  having  the  lemmas  short-awned  or  mucronate,  brown,  and  rather 
firm  in  texture. 

Chlorostis  Raf.,  Princip.  Fondament.  Somiologie  26,  29.  1814.  Proposed 
change  of  name  for  Chloris  Swartz,  because  of  Chlora  L.  (:an  animal) . 

Several  species  are  found  on  the  plains  of  Texas,  where  they  form 
an  unimportant  part  of  the  forage  for  grazing  animals.  Chloris 
verticittata  Nutt.  and  its  allies  are  known  as  windmill  grasses.  The 
mature  inflorescence,  consisting  of  several  slender,  divergent  spikes, 
breaks  away  from  the  plant  and  rolls  before  the  wind  as  a  tumble- 
weed.  In  the  Southwestern  States  is  found  C.  virgata  Swartz  (C. 
elegans  H.  B.  K.)  (fig.  112),  a  tuftecl  annual,  1  to  2  feet  high,  with 
several  pale  or  purplish,  erect,  feathery  spikes  1  to  2  inches  long.  This 
species  invades  cultivated  fields  and  sometimes  becomes  a  rather 
common  weed,  especially  in  alfalfa  fields. 

One  species,  C.  gayana  Kunth,  a  native  of  South  Africa,  is  culti- 
vated to  a  limited  extent  as  a  forage  grass.  This  species,  called 
Rhodes  grass,  has  been  shown  to  have  value  as  a  meadow  grass  in 
the  Southwestern  States.  In  the  Hawaiian  Islands  it  is  used  on  some 
of  the  ranches  in  the  drier  regions.  Rhodes  grass  is  a  perennial,  2 
to  3  feet  high,  producing  long,  stout,  creeping,  propagating  stems  or 
stolons  and  bearing  at  the  summit  of  the  flowering  stems  a  close  fan- 
shaped  cluster  of  numerous  spikes  2  to  4  inches  long. 

For  a  revision  of  the  species  of  Eustachys  and  Chloris  found  in  the 
United  States,  see  Nash,  Bull.  Torrey  Club  25 :  432-450.  1898. 

94.  TRICHLORIS  Fourn. 

Spikelets  1  to  few  flowered,  nearly  sessile,  in  two  rows  along  one 
side  of  a  continuous  slender  rachis,  the  rachilla  disarticulating  above 
the  glumes  and  prolonged  behind  the  uppermost  perfect  floret,  bear- 
ing a  reduced,  usually  awned  floret;  glumes  unequal,  acuminate,  or 
short-awned,  the  body  shorter  than  the  lower  lemma;  lemmas  nar- 
row, 3-nerved,  the  marginal  nerves  sometimes  pubescent,  these  and 
the  midnerve  extending  into  awns,  the  central  long  and  slender,  the 
lateral  often  much  shorter. 

Erect,  slender,  tufted  perennials,  with  flat  blades  and  numerous 
erect  or  ascending  spikes,  aggregate  but  scarcely  digitate  at  the 
summit  of  the  culms.  Species  two  or  three,  in  the  dry  regions  of 
Texas  and  Mexico  and  also  in  Argentina. 


190 


BULLETIN    772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


Type  species :   Trichloris  pluriflora  Fourn. 

Trichloris  Fourn.,  Mex.  PI.   2:  142.     1886.     Fournier   includes  two  specie: 
T.  fasciculata  and  T.  pluriflora,  both  described  as  new.    In  the  generic  descrij 


FIG.   112. — Chloris  viryata.      Plant    X    \  ;   glumes  and   floret  with   rudiment,    X    i 

tion  occurs  the  statement  "  flore  summo  tabescente  mutico."  Under  the  secon 
species  one  finds  "  flore  summo  mutico."  From  this  it  would  appear  tha 
T.  pluriflora  represented  Fournier's  idea  of  the  genus;  hence  this  species  i 
selected  as  the  type. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  191 

Chloropsis  Hack. ;  Kuntze,  Rev.  Gen.  PI.  2 :  771.  1891.  The  name  was  men- 
tioned by  Hackel1  as  a  synonym  under  Trichloris.  Hackel  also  mentions 
Chloridopsis,  both  names  having  been  used  by  gardeners  for  Trichloris  blan- 
chardiana  Hack,  of  Argentina.  Kuntze  changes  the  name  Trichloris  to  Chlor 
opsis,  because  of  the  earlier  Trichlora  Baker.  Both  Trichlora  and  Trichloris 
may  be  considered  valid,  since  they  have  different  derivations  and  slightly 
different  spellings.  Since  Kuntze  adopts  Hackel's  name  and  since  Hackel 
mentions  Chloropsis  blanchardiana,  this  species  is  selected  as  the  type  of 
Chloropsis. 

The  two  species  of  the  United  States,  Trichloris  mendocina  (Phil.) 
Kurtz  (T.  fascieulata  Fourn.)  (fig.  113)  and  T.  plwriflora  Fourn., 
are  found  in  the  arid  regions  of  northern  Mexico  and  extend  into 
western  Texas,  southern  New  Mexico,  and  southern  Arizona.  The 
first  has  spikelets  with  one  perfect  floret  and  a  rudiment,  each  with 
three  long  awns;  the  second  has  spikelets  with  3  to  5  florets,  the 
upper  one  or  two  reduced,  the  lateral  awns  reduced  or  sometimes 
wanting.  Neither  is  of  importance  agriculturally. 

95.  BOTJTELOUA  Lag.,  the  grama  grasses. 

Spikelets  1 -flowered,  with  the  rudiments  of  one  or  more  florets 
above,  sessile,  in  two  rows  along  one  side  of  the  rachis;  glumes  un- 
equal, 1-nerved,  acuminate  or  awn-tipped,  the  first  shorter  and  nar- 
rower; lemma  as  long  as  the  second  glume  or  a  little  longer,  3-nerved, 
the  nerves  extending  into  short  or  often  rather  long  awns,  the  in- 
ternerves  usually  extending  into  teeth;  palea  2-nerved,  sometimes 
2-awned;  rudiment  various,  usually  3-awned,  a  second  rudimentary 
floret  sometimes  present. 

Perennial  or  sometimes  annual,  low  or  rather  tall  grasses,  with  two 
to  several  or  many  spikes  racemose  on  a  common  axis,  or  sometimes 
solitary,  the  spikelets  few  to  many  in  each  spike,  rarely  solitary, 
pectinate  or  more  loosely  arranged  and  appressed,  the  rachis  of  the 
spike  usually  produced  beyond  the  insertion  of  the  spikelets.  Spe- 
cies 38,  all  American  and  chiefly  North  American;  18  species  found 
in  the  United  States,  mostly  in  open  grassland  of  the  southwestern 
States. 

Type  species :  Bouteloita  racemosa  Lag. 

liouteloua  Lag.,  Varied.  Cienc.  Lit.  and  Art.  24:  134.  1805.  Lagasca  gives 
five  species,  B.  racemosa,  B.  hirsuta,  B.  barbata,  B.  simplex,  and  B.  prostrata. 
All  ;;re  briefly  described,  except  the  last,  which  is  mentioned  by  name  only.  The 
first  species  (which  is  the  same  as  B.  curtipendula)  is  selected  as  the  type.  In 
this  work  Lagasca  spells  the  name  of  the  genus  "  Botelua  "  and  states  that  he 
names  the  genus  in  honor  of  the  two  brothers  Boutelou.  In  a  later  work2 
Lagasca  describes  the  genus  under  the  name  Bouteloua,  and  includes  10  species, 
the  first  of  which  is  B.  htysuta.  The  spelling  Bouteloua  is  retained  because  it 
was  corrected  to  this  form  by  the  author  to  correspond  to  the  spelling  of  the 
personal  name  of  the  brothers  Boutelou,  and  because  this  second  spelling  has 
been  universally  accepted  by  botanists. 

Atheropogon  Muhl. ;  Willd.,  Sp.  PI.  4:  937.  1806.  A  single  species  is  described, 
A.  apludioides  Muhl.,  which  is  Bouteloua  curtipendula. 

Triathera  Desv.,  Nouv.  Bull.  Soc.  Philom.  Paris  2:  188.  1810.  Based  on 
Aristida  amtrwana  L.,  which  is  Bouteloua  americana  (L.)  Scribn.,  a  West 
Indian  species. 

*In  Engl.  and  Prantl,  Pflanzeafam.  22:  59.     1887.  2  Gen.  and  Sp.  Nov.  5.     1816. 


192  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  113. — Trichloris  inendoctna.     Plant,   X    J  ;  glumes  and  floret  with  rudiment,   X    5. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  193 

Heterosteca  Desv.,  Nouv.  Bull.  Soc.  Philom.  Paris  2:  188.  1810.  Based  on 
//.  juncifolia,  which  is  Bouteloua  heterostega  (Trin.)  Griffiths,  of  the  West 
Indies. 

Chondrosium  Desv.,  Nouv.  Bull.  Soc.  Philom.  Paris  2 :  188.  1810.  Based  on 
Chloris  procumbens  Durand  (Bouteloua  procumbens). 

Polyodon  H.  B.  K.,  Nov.  Gen.  and  Sp.  1 :  174,  pi.  55.  1816.  Based  on  a  single 
species,  P.  distichum  H.  B.  K. 

Triaena  H.  B.  K.,  Nov.  Gen.  and  Sp.  1 :  178.  1816.  A  single  species  described, 
T.  racem<osa,  which  is  Bouteloua  triaena  (Trin.)  Scribn. 

Eutriana  Trin.,  Fund.  Agrost.  161.  1820.  Trinius  includes  two  species,  E. 
curtipendula  and  E.  bromoides.  The  first  is  selected  as  the  type. 

The  species  fall  into  two  rather  well  marked  divisions,  those  in 
which  the  spikelets  are  crowded  and  pectinate  and  the  spikes  persist- 
ent on  the  main  axis,  the  florets  falling,  and  those  in  which  the 
spikelets  are  less  crowded,  ascending  rather  than  pectinate  on  the 
rachis,  and  the  spikes  falling  entire.  Bouteloua  gracilis  and  its 
allies  are  examples  of  the  first  group  and  B.  filiformis  (Fourn.) 
Griffiths  and  its  allies,  B.  curtipendula  and  B.  aristidoides  of  the  sec- 
ond. The  genus  is  important,  since  many  of  the  species  are  the 
chief  ingredient  of  the  grazing  lands  of  the  Southwestern  States. 

Bouteloua  gracilis  Lag.  (B.  oligostachya  Torr.)  (fig.  114)  is 
found  on  the  Great  Plains  from  Manitoba  to  Mexico  and  even  south- 
ward to  South  America.  It  is  the  blue  grama  of  the  ranchmen  and, 
along  with  buffalo  grass  (Bulbilis  dactyloides}  and  curly  mesquite 
(Hilaria  belangeri) ,  constitutes  most  of  what  is  known  in  the  Middle 
West  as  "short-grass."  Blue  grama  is  a  tufted  perennial,  with 
numerous  short  leaves  and  a  flower  stalk  about  a  foot  high  with  2 
or  3  spikes  about  an  inch  long.  These  spikes,  one  at  the  end  of  the 
stem  and  the  other  one  or  two  a  short  distance  below,  turn  with  the 
wind  like  weather  vanes.  An  allied  species,  B.  Mrsuta  Lag., 
called  black  grama,  is  found  over  about  the  same  region,  but  is  con- 
fined chiefly  to  rocky  hills.  This  species  differs  in  having  shorter, 
niore  fuzzy  spikes  and  in  the  prolonged  end  of  the  rachis,  which 
forms  a  distinct  point  beyond  the  spikelets. 

Another  widely  distributed  species  is  Bouteloua  curtipendula 
(Michx.)  Torr.  (B.  racemosa  Lag.)  (fig.  115),  called  side-oats 
grama.  It  extends  farther  east  than  the  other  species,  being  found 
even  as  far  as  Connecticut.  Side-oats  grama  is  the  tallest  of  the 
species,  sometimes  as  much  as  3  feet,  and  is  further  distinguished 
by  the  numerous  (35  to  50)  short,  reflexed  spikes. 

In  Arizona  and  New  Mexico  other  species  become  prominent. 
Bouteloua  eriopoda  Torr.,  called  here  black  grama  and  woolly-foot, 
is  a  low  creeping  species  with  woolly  stem.  Bouteloua  rothrockii 
Vasey  is  the  most  important  range  grass  in  many  parts  of  Arizona. 
It  grows  about  a  foot  high  and  has  five  or  six  spikes  to  each  culm. 
In  B.  texana  S.  Wats.,  of  the  Texas  plains,  the  short  triangular 
spikes  fall  from  the  axis  entire. 
97769°— 19— Bull.  772 13 


194  BULLETIN   772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 


Three  species  are  annuals,  B.  aristidoides  Thurb.,  B.  procumbens 
(Durand)  Griffiths  (B.  prostrata  Lag.),  and  B.  barbvta  Lag.  (B. 
polystachya  Torr.).  These  are  found  from  Texas  to  Arizona,  where 
they  are  called  six-weeks  grama.  They  furnish  forage  when  young, 
but  are  of  secondary  importance. 

For  a  revision  of  the  spe- 
cies of  Bouteloua  and  its 
allies,  see  Griffiths,  Contr. 
U.  S.  Nat.  Herb.  14:343- 
424.  1912.  Economic  notes 
and  synonymy  are  included. 

96.  CATHESTECUM  Presl. 

Spikes  consisting  of  3 
spikelets,  the  upper  or  cen- 
tral perfect,  the  2  lateral 
stammate  or  rudimentary, 
the  spike  falling  entire; 
central  spikelet  with  one 
perfect  floret  below  and  one 
or  more  reduced  florets 
above;  glumes  unequal,  the 
first  a  short,  thin,  nerveless 
scale  in  the  central  spikelet, 
narrow  and  acuminate  in 
the  lateral  spikelets,  the 
second  about  as  long  as  the 
lemma,  acuminate,  all  usu-" 


FIG.   114. — Blue  grama,  Bouteloua  gracilis.     Plant,    X    2 
glumes,  floret  with  rudiment,  and  floret  alone,   X   5. 


ally  villous;  lemma  3-nerved,  or  rarely  5  to  7  nerved,  the  nerves 
extending  into  awns,  and  the  internerves  into  teeth ;  palea  2-nerved, 
the  nerves  extending  into  short  awns;  second  and  third  floret  with 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


195 


a   fairly   well   developed  lemma   and   palea,   the   fourth   floret,   if 
present,  usually  reduced. 

Low  cespitose  or  stoloniferous 
annuals  or  perennials,  with  short 
blades,  and  several  or  many  short 
deciduous  spikes  scattered  along 
the  main  axis.  Species  four,  on  the 
Mexican  Plateau,  one  extending 
into  western  Texas. 


FIG.    115. — Side-oats  grama,   Bouteloua  curtipendula.     Plant,    X    \  ;   spikelet   and   floret 

with  rudiment,    X    5. 

Type  species:  Cathestccum  prostratum  Presl. 

Cathestecum  Presl,  Rel.  Haenk,  1;  294,  pi.  42.     1830.     Only  one  species  de- 
scribed. 


196  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

The  only  species  found  in  the  United  States  is  Cathestecwn  erec- 
tum  Vasey  and  Hack.  (fig.  116),  a  stoloniferous  perennial  with  the 
aspect  of  Bouteloua  texcma  but  more  delicate.  This  species  is  known 
in  western  Texas  from  a  very  few  collections,  but  is  more  common 


FIG.  HG.—Cathestecum  erectum.     Plant,  X   I  ;  group  of  spikelets  (reduced  spike),  central 
spikelet,  and  fertile  floret,   X   5. 

in  northern  Mexico.  Cathestecum  is  placed  by  Bentham1  doubt- 
fully in  the  tribe  Zoysieae,  and  by  Hackel 2  in  the  tribe  Festuceae. 
Griffiths3  shows  its  affinity  to  Bouteloua  and  places  it  in  the  tribe 
Chlorideae. 

1Benti-.  and  Hook.  Gen.  PI.  3:  1122.     1883. 
2Engl.  and  Prantl,  Pflanzenfam.  22:  65.     1887. 
3Contr.  U.  S.  Nat,  Herb.  14:  358.     1912, 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  197 

97.  MUNROA  Torr. 

Spikelets  in  pairs  or  threes  on  a  short  rachis,  the  lower  one  or  two 
larger,  3  or  4  flowered,  the  upper  2  or  3  flowered,  the  group  (reduced 
spikes)  inclosed  in  the  broad  sheaths  of  short  leaves,  usually  about 
3  in  a  fascicle,  forming  a  cluster  or  head  at  the  ends  of  the 
branches;  rachilla  disarticulating  above  the  glumes  and  between  the 
florets ;  glumes  of  the  lower  1  or  2  spikelets  equal,  1-nerved,  narrow, 
acute,  a  little  shorter  than  the  lemmas,  those  of  the  upper  spikelet 
unequal,  the  first  much  shorter  or  obsolete;  lemmas  3-lierved,  those 
of  the  lower  spikelet  coriaceous,  acuminate,  the  points  spreading,  the 
midnerve  extended  into  a  mucro,  those  of  the  upper  spikelet  mem- 
branaceous ;  palea  narrow,  2-nerved,  inclosing  the  oval,  dorsally  com- 
pressed caryopsis. 

Low  spreading,  much-branched  annuals,  the  short,  flat,  pungent 
leaves  in  fascicles.  Species  three,  plains  of  America ;  two  in  Argen- 
tina, one  in  the  western  United  States. 

Type  species :  Crypsis  squarrosa  Nutt. 

Munroa  Torr.,  U.  S.  Rep.  Expl.  Miss.  Pac.  4:  158.  1856.  One  species  de- 
scribed, M.  squarrosa  (Nutt.)  Torr.  Torrey  spells  the  genus  Monroa,  naming  it 
in  honor  of  Munro,  whom  he  refers  to  erroneously  as  Major  "  Monro." 

The  prophylla  are  prominent  in  the  fascicles  of  leaves,  the  two 
nerves  extending  into  long,  green  tips.  The  lower  spikelet  is  bulged 
out  on  the  lower  side,  throwing  the  glumes  forward;  thus  they 
appear  somewhat  asymmetric.  This  genus  has  hitherto  been  placed 
in  Festuceae,  but  the  structure  of  the  spikelet  and  spike  show  closer 
affinity  to  genera  of  Chlorideae. 

Munroa  squarrosa  (fig.  117)  is  common  on  the  Great  Plains  from 
Montana  to  northern  Mexico,  usually  in  new  soil  and  open  ground. 
It  has  little  or  no  importance  as  a  forage  grass.  It  is  sometimes 
abundant  on  recently  broken  sod.  Munroa  mendocina  Phil.,  of 
Argentina,  has  been  referred  to  M.  squarrosa,  but  it  is  a  distinct 
species. 

98.  BULBILIS  Eaf. 
(BucMoe  Engelm.) 

Plants  unisexual.  Staminate  spikelets  2-flowered,  sessile  and 
closely  imbricate,  in  two  rows  on  one  side  of  a  slender  rachis  forming 
a  short  spike;  glumes  somewhat  unequal,  rather  broad,  1-nerved, 
acutish;  lemmas  longer  than  the  glumes,  3-nerved,  rather  obtuse, 
whitish;  palea  as  long  as  its  lemma,  2-nerved.  Pistillate  spikelets 
mostly  3  to  5  in  a  short  spike  or  head,  this  falling  entire,  usually 
2  heads  to  the  inflorescence,  the  common  peduncle  short  and 
included  in  the  somewhat  inflated  sheaths  of  the  upper  leaves,  the 
thickened  somewhat  woody  rachis  and  the  2  or  3  outer  (second) 
glumes  appearing  like  an  involucre;  glumes  very  unequal,  the  first 
inside  relative  to  the  cluster,  thin,  1-nerved,  keeled,  the  nerve  extend- 


198  BULLETIN   772,   U.    S.   DEPARTMENT   OF   AGRICULTURE. 

ing  into  a  point  or  awn,  as  long  as  the  lemma  or  reduced  in  some  of 
the  spikelets  or  wanting,  the  second  glume  firm,  thick  and  woody, 
almost  surrounding  the  remainder  of  the  spikelet,  rounded  on  the 
back,  white  or  yellowish,  obscurely  nerved,  the  margins  inflexed,  thin, 
ciliate,  the  upper  part  greenish,  acuminate,  spreading,  with  one  or 
two  teeth  at  the  sides;  lemma  firm-membranaceous,  3-nerved,  dor- 
sally  compressed,  broad  below,  narrowed  into  a  3-lobed  green  summit, 
the  middle  lobe  much  the  larger ;  palea  2-nerved,  broad,  obtuse,  about 
as  long  as  the  body  of  the  lemma,  enveloping  the  caryopsis. 


Fio.  117. — Munroa  sguarrosa. 


Plant,   X    \\  group  of  spikelets   (reduced  spike), 
and  floret,    X    5. 


spikelet, 


A  low  stoloniferous  perennial,  with  short  curly  blades,  the 
staminate  flowers  in  two  or  three  short  spikes  on  slender,  erect  culms, 
the  pistillate  in  sessile  clusters  partly  hidden  among  the  leaves. 
Species  one,  on  the  Great  Plains  from  Montana  to  Mexico. 

Type  species :  Seslqria  dactyloides  Nutt. 

Bulbilis  Raf.,  Amer.  Month.  Mag.  4:  190.  1819.  Rafinesque  gives  a  review 
of  Nuttall's  Genera  of  North  American  Plants.  The  part  relating  to  Bulbilis  is, 
"  Sesleria  dactyloides  must  form  a  peculiar  genus  by  Mr.  N's  own  account,  it 
may  be  called  Bulbilis." 

Calanthera  Kunth,  in  Hook.  Kew  Journ.  8:  18.  1856.  A  single  species  in- 
cluded, "  G.  dactyloides  Kth. — Nutt.  Sesleria  .  .  .  Buffalo  grass." 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  199 

Buchloe  Engelm.,  Trans.  Acad.  St.  Louis  1:  432.  1859.  Based  on  Sesleria 
dactyloides.  Engelmann  gave  the  first  description  of  the  genus.  Nuttall's  de- 
scription of  Seslcria  dactyloides  was  based  on  the  staminate  plant. 

The  species  is  usually  described  as  dioecious  *  because  the  staminate  and  pis- 
tillate flowers  are  found  on  different  individuals.  Experiments  in  growing  the 
plants  from  seed  show  that  they  are  monoecious,  the  two  kinds  of  flowers  aris- 
ing from  distinct  branches  which  propagate  vegetatively,  each  branch  produc- 
ing its  own  kind.2  Plank 3  observed  that  seedlings  were  monoecious. 

Bulbilis  dactyloides  (Nutt.)  Raf.  (Buchloe  dactyloides  Engelm.) 
(fig.  118),  commonly  known  as  buffalo  grass,  is  one  of  the  chief 
constituents  of  the  sod  on  the  Great  Plains.  It  forms,  when  unmixed 
with  other  grasses,  a  close,  soft,  grayish  green  turf.  Buffalo  grass 
is  dominant  over  large  areas  on  the  uplands,  colloquially  known  as 
the  "  short-grass  country,"  and  is  one  of  the  most  important  grazing 
grasses  of  this  region.  The-  sod  houses  of  the  early  settlers  were 
made  mostly  from  the  sod  of  this  grass. 

8.  PHALARIDEAE,  THE  CANARY-GRASS  TRIBE. 

99.  TORKESIA  Ruiz  and  Pav. 
(Hierochloe  R.  Br.,  Savastana  Schrank.) 

Spikelets  with  one  terminal  perfect  floret  and  two  staminate  flo- 
rets, disarticulating  above  the  glumes,  the  staminate  florets  falling 
attached  to  the  fertile  one;  glumes  equal,  broad,  thin  and  papery, 
smooth,  acute;  sterile  lemmas  about  as  long  as  the  glumes,  mostly 
somewhat  appressed-hispid,  sometimes  awned  from  between  two 
lobes ;  fertile  lemma  somewhat  indurate,  about  as  long  as  the  others, 
smooth  or  nearly  so,  awnless;  palea  3-nerved,  rounded  on  the  back-. 

Perennial,  low,  erect,  sweet-smelling  grasses,  with  small  panicles  of 
bronze-colored  spikelets.  Species  about  17,  confined  to  cool  and, 
alpine  regions ;  3  species  in  the  United  States. 

Type  species :  Torresia  utriculata  Ruiz  and  Pav. 

Savastana  Schrank,  Baier.  Fl.  1:  100,  337,  1789,  not  Savastania  Scop.,  1777. 
Type,  8.  hirta  Schrank,  the  only  species  described. 

Torresia  Ruiz  and  Pav.,  Syst.  Veg.  Peruv.  Chil.  251.  1798.  A  single  species 
described. 

Hierochloe  R.  Br.,  Prodr.  Fl.  Nov.  Holl.  208.  1810.  Type,  Disarrenum 
antarcticum  Labill.  upon  which  is  based  the  only  species  described  (H.  antarc- 
tica).  Later  authors  have  often  spelled  this  Hierochloa. 

Dimesia  Raf.,  Amor.  Month.  Mag.  2 :  175.  1818.  Based  on  "  Holcus  fra  grans 
of  Pursh's  Flora."  This  is  the  same  as  Torresia  odorata. 

The  common  species,  Torresia  odorata  (L.)  Hitchc.  (Hierochloe 
odorata  Wahl.,  II.  borealis  Koem.  and  Schult.)  (fig.  119),  called  holy 
grass,  vanilla  grass,  or  Seneca  grass,  grows  in  Canada  and  the  north- 
ern part  of  the  United  States.  Like  all  the  species  of  the  genus  and 
the  allied  genus  Anthoxanthum,  it  is  sweet  scented,  owing  to  the 

1  Pilger  discusses  this  and  other  species  in  a  paper  on  monoecious  and  dioecious  grass 
genera.     Bot.  Jahrb.  Engler  84 :  377.     1904. 

2  Hitchcock,  Bot.  Gaz.  20:  464.     1895.-  3  Bull.  Torrey  Club  19:  303.     1892. 


200  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


FIG.  118. — Buffalo  grass,  Bulbilis  dactyloides.  Pistillate  plant  (above),  X  J;  group  of 
pistillate  spikelets  (reduced  spike),  and  floret,  X  5;  staminate  plant  (below),  X  J; 
staminate  spikelet,  X  5. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES. 


201 


presence  of  coumarin.    The  Indians  use  the  grass  to  make  fragrant 

baskets. 

Torresfa  alpina  (Swartz)  Hitchc.,  with  small,  condensed  panicles 

and  awned  staminate  florets,  is  arctic  and  extends  to  the  alpine  peaks 

of  New  York  and  New  England;  T. 
macrophylla  (Thurb.)  Hitchc.,  with 
broad  blades,  is  Californian. 

100.  ANTHOXANTHUM  L, 

Spik'elets  with  1  terminal  perfect 
floret  and  2  sterile  lemmas,  the  rachilla 
disarticulating  above  the  glumes,  the 
sterile  lemmas  falling  attached  to  the 
fertile  floret;  glumes  unequal,  acute 
or  mucronate;  sterile  lemmas  shorter 
than  the  glumes,  empty,  awned  from 
the  back;  fertile  lemma  shorter  than 
the  sterile  ones,  awnless;  palea  1- 
nerved,  rounded  on  the  back,  inclosed 
in  the  lemma. 

Sweet-smelling  annual  or  perennial 
grasses,  with  flat  blades  and  spikelike 
panicles.    Species  about  four, 
Europe  and  Asia;  two  intro- 
duced into  the  United  States. 

Type  species :  Anthoxanthwtn 
odoratum  L. 

Anthoxanthum  L.,  Sp.  PI.  28, 
1753;  Gen.  PI.,  ed.  5,  17.  1754. 
Linnaeus  describes  three  species, 
A.  odoratum,  A.  indicum,  and  A. 
paniculatum.  The  first  is  chosen 
as  the  type.  The  second  species  is 
now  referred  to  Perotis  and  the 
third  to  Festuca. 


FIG.  119. — Vanilla  grass,  Torresia  odorata.     Plant,  X  \  ;  spikelet,  florets  with  the  glumes 
'removed,  and  fertile  floret,   X   5. 

Anthoxanthum  odoratum,  sweet  vernal  grass  (PI.  XV;  fig.  120),  is 
sometimes  included  in  meadow  mixtures  to  give  fragrance  to  the  hay. 


202  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


The  grass  has  no  forage  value.    It  is  now  common  along  roadsides 
and  in  grassland  throughout  the  Eastern  States.    Like  the  species  of 

Torresia  it  has  an  aromatic  odor  due  to  the 
presence  of  coumarin.  Sweet  vernal  grass 
is  an  erect  perennial,  about  a  foot  high.  An- 
other species,  A.  aristatum  Boiss.  (.4.  puelln 
Lee.  and  Lam.),  a  low  annual,  is  introduced 
at  a  few  localities. 

101.  PHALAKIS  L. 

Spikelets    laterally    compressed,    with    1 
terminal  perfect  floret  and  2  sterile  lemmas 
below,  disarticulating  above  the  glumes,  ar- 
.  ranged  in  usually  dense  spikelike  panicles ; 
glumes  equal,  boat  shaped,  often  winged  on 
the  keel;  sterile  lemmas  reduced  to  2  small 
scales  (rarely  only  1) ;  fertile  lemma  coriace- 
ous, shorter  than  the  glumes, 
inclosing  the  faintly  2-nerved 
palea. 

Annual  or  perennial  erect 
grasses,  with  flat  blades. 
Species  about  20,  in  temper- 
ate regions  of  Europe  and 
America.  Nine  species  are 
found  in  the  United  States, 
four  being  introduced  from 
Europe. 

Type  species :  Plialaris  canari- 
ensis  L. 

Phalaris  L.,  Sp.  PI.  54,  1753; 
Gen.  PI.,  ed.  5,  29.  1754.  Five 
species  are  described,  P.  canari- 


FIG.   120.  —  Sweet  vernal   grass,   Anthoxantlium   odoratum.      Plant,    X 
sterile  lemmas,  and  fertile  floret,  X  5. 


spikelet,   two 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XV. 


SWEET  VERNAL  GRASS  (A  NTH  ox  A  NTH  DM  ODORATUM). 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XVI. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


203 


ensis,  P.  phleoidcs,  P.  arundinacea,  P.  erucaeformis,  and  P.  oryzoides.  The 
second  species  is  now  referred  to  Phleum,  the  fourth  to  Beckmannia,  and 
the  fifth  to  Homalocenchrus.  The  first  species  is  chosen  as  the  type,  be- 
cause this  is  the  one  that  best  corresponds  to  the  description  of  the  genus 


in  the  Genera  Plantarum 
(e.  g.,  gluma  obtusa)  and 
is  moreover  the  only  one 
of  the  five  species  men- 
tioned above  that  was 
known  by  the  name  of 
Phalaris  to  the  older  au- 
thors, such  as  Bauhin. 

Typhoides  Moench, 
Meth.  201.  1794.  A  single 
species,  T.  arundinacea, 
based  on  Phalaris  arundi- 
nacea L.,  is  included. 

Digraphis  Trin.,  Fund. 
Agrost.  127.  1820.  A 
single  species,  D.  arundi- 
nacea, based  on  Phalaris 
arundinacea  L.,  is  in- 
cluded. 

Endallax  Rat,  Bull.  Bot.  Seringe 
1:  220.  1830.  Phalaris  arundinacea 
is  the  only  species  given. 

The  most  important  species  of 
the  genus  in  the  United  States  is 
Phalaris  arundinacea  L.,  reed 
canary  grass,  a  native  perennial 
found  in  wet  ground  in  the 
cooler  parts  of  the  Northern 
Hemisphere.  The  inflorescence 
is  a  rather  loose  spikelike  panicle 
2  to  6  inches  long.  It  is  an  im- 
portant constituent  of  lowland 
hay  in  the  region  from  Mon- 
tana to  Wisconsin.  A  vari- 
ety (picta  L.)  with  blades 
striped  with  white  is  grown  for 

ornament  in  gardens  under  the  name  of  ribbon  grass  or  gardener's 

garters. 


FIG.  121. — Canary  grass, 
canariensis.  Plant,  X  \ 
and  fertile  floret  with 
sterile  lemmas,  X  5. 


Phalaris 
;  spikelet 
tbe  two 


204  BULLETIN   772,    U.   S.    DEPARTMENT   OF   AGRICULTURE. 

Phalaris  canariensis  L.  (fig.  121),  canary  grass,  is  an  annual  with 
ovoid  heads,  the  large  spikelets  white  with  green  nerves.  This  species 
is  introduced  from  Europe,  where  it  is  grown  for  seed,  which  fur- 
nishes the  canary  seed  of  commerce.1  Phalaris  caroliniana  Walt.,  a 
perennial  of  the  southern  United  States,  with  oblong  compact  heads, 
is  sometimes  cultivated  for  winter  forage. 

9.  ORYZEAE,  THE  RICE  TRIBE. 

102.  ORYZA  L. 

Spikelets  1-flowered,  laterally  compressed,  disarticulating  be- 
low the  glumes;  glumes  2,  much  shorter  than  the  lemma,  narrow; 
lemma  rigid,  keeled,  3-nerved,  sometimes  awned ;  palea  similar  to  the 
lemma,  narrower,  keeled,  but  with  no  midnerve  on  the  back,  2-nerved 
close  to  the  margins. 

Annual  or  sometimes  perennial  swamp  grasses,  often  tall,  with  flat 
blades  and  spikelets  in  open  panicles.  Species  about  seven,  one  in 
tropical  America,  the  others  in  tropical  Africa  and  Asia. 

Type  species :  Oryza  sativa  L. 
Oryza  L.,  Sp.  PI.  333,  1753;  Gen.  PL,  ed.  5,  155.     1754.     A  single  species,  0. 
sativa,  is  described. 

The  only  important  species  is  Oryza  sativa  L.  (fig.  122),  or  rice. 
This  is  cultivated  in  all  tropical  and  warm  countries  and  is  one  of  the 
important  food  plants  of  the  world.  There  are  a  large  number  of 
varieties,  some  with  awned,  some  with  awnless  spikelets.  In  the 
United  States  rice  is  grown  under  irrigation  on  the  lowland  along 
the  Atlantic  -coast  of  the  Southern  States,  especially  in  South  Caro- 
lina and  Georgia,  and  more  extensively  along  the  Mississippi  River 
in  Louisiana  and  on  the  prairies  of  southwestern  Louisiana  and 
southeastern  Texas. 

103.    HOMALOCENCHKUS    Mieg. 

(Leersia  Swartz.) 

Spikelets  1-flowered,  strongly  compressed  laterally,  disarticulating 
from  the  pedicel;  glumes  wanting;  lemma  chartaceous,  broad,  ob- 
long, boat  shaped,  usually  5-nerved,  the  lateral  pair  of  nerves  close 
to  the  margins,  these  and  the  keel  often  hispid-ciliate,  the  interme- 
diate nerves  sometimes  faint ;  palea  as  long  as  the  lemma,  much  nar- 
rower, usually  3-nerved,  the  keel  usually  hispid-ciliate,  the  lateral 
nerves  close  to  the  margins,  the  margins  firmly  held  by  the  margins 
of  the  lemma ;  stamens  six  or  fewer. 

Perennial  grasses,  usually  with  creeping  rhizomes,  with  flat,  sca- 
brous blades  and  open  panicles,  the  spikelets  nearly  sessile  along  one 

lrThe  commercial  seed  may  also  contain  seed  of  Panicum  miliaceum.  The  seed  of 
Phalaris  canariensis  is  pale  yellow,  equally  convex  on  both  sides,  compressed,  and  some- 
what pubescent.  The  seed  of  Panicum  miUaceum  is  brownish  or  reddish,  much  more 
plump,  dorsally  flattened  on  one  side,  smooth,  and  faintly  nerved. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


205 


side  of  the  branchlets.    Species  ten,  tropical  and  temperate  regions; 
five  species  in  the  United  States,  mostly^  swamp  grasses. 

Type  species:  Phalaris  oryzoides  L. 

Homalocenchrus  Mieg,  Act.  Helv. 
Phys.  Math.  4:  307.  1760.  One  spe- 
cies is  referred  to  the  genus  with  cer- 
tainty, another  being  doubtfully  re- 
ferred to  it.  No  specific  names  are 
used,  but  under  the  first  there  are  two 
citations  which  appear  in  the  Species 
Plantarum  under  Phalaris  oryzoides. 

Leersia  Swartz,  Prod.  Veg.  Ind.  Occ. 
21.  1788.  Three  species  are  de- 
scribed, L.  monandra,  L.  hexandra, 
and  L.  oryzoides.  Phalaris  oryzoides 


FIG.  122. — Rice,   Oryza  saliva.     Plant,    X    I  ;  spikelet,    X    5. 

L.,  the  basis  of  the  third  species,  is  selected  as  the  type,  as  this  is  the  oldest 
historically. 


206  BULLETIN    772,   TJ.    S.   DEPARTMENT   OF   AGRICULTURE. 

Endodia  Raf.,  Neogenyt.  4.  1825.  Based  on  Leersia  lenticiilaris,  the  only 
species  mentioned. 

Aplexla  Raf.,  Bull.  Bot.  Seringe  1:  220.  1830.  A  single  species,  Leersia 
virgata  (probably  a  misprint  for  L.  virginica)  is  included. 

All  the  species  of  the  United  States  except  H  omalocenchrus  monan- 
drus  (Swartz)  Kuntze,  a  plant  of  rich  woods  in  southern  Florida  and 
southern  Texas,  have  creeping  rhizomes.  Most  of  them  are  marsh 
grasses.  H  omalocenchrus  monandrus  differs  from  the  other  species 
also  in  having  small  glabrous  spikelets  in  which  the  palea  is  rounded 
on  the  back  and  lacks  the  midnerve,  as  in  rice.  In  the  other  species 
the  palea  is  strongly  compressed-keeled  and  appears  to  represent  a 
bract  rather  than  a  prophyllum. 

H  omalocenchrus  virginicus  (Willd.)  Britton  and  H.  oryzoides 
(L.)  Poll.  (fig.  123)  are  common  throughout  the  eastern  United 
States  in  moist  soil,  the  latter  often  forming  distinct  zones  of  vege- 
tation in  marshes.  The  first  has  spikelets  about  3  mm.  long  and  the 
main  panicle  branches  solitary ;  the  second  has  spikelets  about  5  mm. 
long  and  the  lower  main  panicle  branches  more  than  one  at  the  node. 
These  species,  because  of  the  very  scabrous,  adhesive  blades,  are 
called  rice  cut-grass.  The  species  have  no  economic  importance. 

10.  ZIZANIEAE,  THE  INDIAN-RICE  TRIBE. 

104.  ZIZANIOPSIS  Doell  and  Aschers. 

Spikelets  unisexual,  1-flowered,  disarticulating  from  the  pedicel, 
mixed  on  the  same  branches  of  the  panicle,  the  staminate  below; 
first  glume  wanting;,  second  glume  7-nerved,  short-awned  in  the 
pistillate  spikelets;  lemma  3-nerved;  palea  wanting;  stamens  six; 
styles  rather  long,  united;  caryopsis  obovate,  free,  coriaceous, 
smooth  and  shining,  beaked  with  the  persistent  style. 

Robust  perennial  marsh  grasses,  with  stout  creeping  rhizomes, 
broad  flat  blades,  and  large  open  panicles.  Species  three;  two  in 
South  America,  one  in  the  United  States. 

Type  species:  Zizania  microstacJiya  Nees. 

Zizaniopsis  Doell  and  Aschers.;  Doell  in  Mart.  Fl.  Bras.  22:  12,  pi.  3.  1871. 
A  single  species  described. 

The  only  species  in  the  United  States  is  Zizaniopsis  miliacea 
(Michx.)  Doell  and  Aschers.  (fig.  124),  growing  in  swamps  from  Vir- 
ginia to  Florida  and  Texas.  Like  Zizania  palustris,  which  it  some- 
what resembles,  this  species  may  be  gregarious  over  wide  areas.  It 
has  no  economic  importance  except  as  it  may  furnish  shelter  and  food 

to  water  birds. 

105.  ZIZANIA  L. 

Spikelets  unisexual,  1-flowered,  disarticulating  from  the  pedicel; 
staminate  spikelet  soft,  the  first  glume  wanting,  the  second  5-nerved, 
membranaceous,  linear,  acuminate  or  awn-pointed;  lemma  about  as 
long  as  the  glume,  3-nerved;  palea  wanting;  stamens  6;  pistillate 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  207 


FIG.  123, — Rice  cut-grass,  Homaloccnchrus  oryzoides.     Plant,   X    £  ;  spikelet,   X  5. 


208  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


FIG.  124. — Zizaniopsis  miliacea.     Plant,    X    I  ;  staminate  spikelet,  pistillate  spikelet,  and 

ripe  caryopsis,    X    5. 


GENERA  OF   GRASSES  OF  THE   UNITED  STATES.  209 

spikelet  terete,  angled  at  maturity:  glumes  wanting;  lemma  charta- 
ceous,  3-nerved,  tapering  into  a  long  slender  awn;  palea  2-nerved, 
closely  clasped  by  the  lemma;  grain  cylindric,  as  much  as  2  cm.  long.. 
Tall  annual  or  perennial  aquatic  grasses,  with  flat  blades  and  large 
terminal  panicles,  the  lower  branches  spreading,  bearing  the  pendu- 
lous staminate  spikelets,  the  upper  branches  ascending,  at  maturity 
erect,  bearing  appressed  pistillate  spikelets,  the  staminate  spikelets 
early  deciduous,  the  pistillate  spikelets  tardily  deciduous.  Species 
three,  one  in  eastern  Asia,  two  in  North  America. 

Type  species:  Zissania  aquatica  L. 

Zizania  L.,  Sp.  PI.  991,  1753 ;  Gen.  PI.,  ed.  5r  427.  1754.  Linnaeus  describes 
two  species,  Z.  aquatica  and  Z.  terrcstris.  The  citation  in  the  Genera  Plantarum 
is  to  Gronovius.  "  Zizania  Gron.  virg.  189  "  is  given  as  a  synonym  by  Linnaeus 
under  Z.  aquatica;  hence  the  latter  is  the  type  species.  The  second  species,  from 
Malabar,  does  not  belong  to  Zizania.  The  director  of  the  Kew  Royal  Botanic 
(jraraens  states  that  the  plate  upon  which  it  is  based  (Rheede,  Hort.  Malab.  12: 
pi.  60)  represents  Scleria  elata  Thwaltes. 

Fartis  Adans.,  Fam.  PI.  2:  37,  557.  1763.  Based  on  Zizania  L.,  which  was 
not  Zizania  of  the  ancients. 

Hydropyrum  Link,  Hort.  Berol.  1:  252.  1827.  A  single  species,  H.  esculen- 
tum,  based  on  Zizania  palustris  L.,  is  included. 

Melinum  Link,  Handbuch  Erkenn.  Gewachse  1 :  96.  1829.  A  single  species, 
M.  palustre,  based  on  Zizania  palustris  L.,  is  included. 

Ceratochaete  Lunell,  Amer.  Midi.  Nat.  4:  214.  1915.  A  new  name  proposed 
for  Zizania  L.,  "not  Zizanion  of  the  New  Testament,"  which  is  the  tares  of 
Scripture. 

Zizania  palustris  L.  (PI.  XVI;  fig.  125),  Indian  or  wild  rice,  is  an 
annual  marsh  grass  growing  in  the  Eastern  and  Northern  States, 
often  over  extensive  areas.  The  seeds  were  used  by  the  aborigines  for 
food  and  are  still  used  to  some  extent  by  some  of  the  northern 
tribes  of  Indians.  Wild  rice  is  important  as  a  food  and  shelter  for 
water  birds.  It  is  sometimes  planted  for  this  purpose  in  marshes  on 
game  preserves.  Zizania  aquatica  L.  differs  in  having  narrower 
blades,  shorter  culms,  and  less  spreading  panicles.  This  form,  found 
from  Maine  to  Minnesota,  may  be  a  variety  rather  than  a  distinct 
species.1  At  first  Linnaeus  did  not  distinguish  between  the  narrow- 
leaved  and  broad-leaved  forms,  but  based  the  name  aquatica  on  a 
specimen2  of  the  narrow-leaved  form.  Later  (1771)  he  described  the 
broad-leaved  form  as  Zizania  palustris.  The  Asiatic  Z.  latifolia 
Turcz.  is  a  perennial  with  rhizomes  and  stolons. 

106.  LUZIOLA  Juss. 

Spikelets  unisexual,  1-flowered,  disarticulating  from  the  pedicel, 
the  staminate  and  pistillate  flowers  in  separate  panicles  on  the  same 
plant ;  first  glume  and  palea  wanting ;  second  glume  and  lemma  about 
equal,  thin,  several  to  many  nerved,  lanceolate  or  oblong;  stamens 
several  ( "  6  to  18 "  ) ;  stigmas  long,  plumose ;  grain  free,  globose, 
smooth. 

lSee  Smiths.  Misc.  Coll.  6812:  35.     1918. 

2  See  Hitchcock,  Contr.  U.  S.  Nat.  Herb.  12:  124.     1908, 

97769°— 19— Bull.  772 14 


210  BULLETIN   772,   U.    S.   DEPARTMENT  OF   AGRICULTURE. 


FIQ.  125.— Wild  rice,  Zizania  palustris.     Plant,   X    I  ;  pistillate  spikelet,    X   2  ;  a  second 
view,  X  5  ;  staminate  spikelet,  X  5, 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  211 

Perennial,  creeping,  low  or  delicate  grasses,  with  narrow,  flat  blades 
and  terminal  and  axillary  panicles.  Species  about  six,  in  tropical 
America ;  two  species  in  the  southern  United  States. 

Type  species:  Luziola  peruriann  Gmel. 

Luzioln  Juss. ;  Gmel.  Syst.  Nat.  2:  637.  1791.  The  genus  is  first  described 
by  Jussieu  in  his  Genera  Plantarum  (1789),  but  no  specific  name  *s  mentioned. 
Ginelin  assigns  a  specific  name  to  the  species  described  by  Jussieu. 

There  are  two  species  in  the  United  States,  Luziola  peruviana 
(fig.  126),  with  fruit  2  mm.  long,  and  L.  cdabamemis  Chapm.,  with 
fruit  4  mm.  long,  the  former  from  Florida  to  Louisiana  and  the  latter 
from  Alabama.  They  have  no  economic  importance. 

107.  HYDBOCHLOA  Beauv. 

Spikelets  unisexual,  1-flowered,  awnless,  disarticulating  from  the 
pedicel,  the  plants  monoecious;  staminate  spikelets  with  a  thin 
7-nerved  lemma,  a  2-nerved  palea,  and  6  stamens,  the  glumes  want- 
ing; pistillate  spikelets  with  a  thin  3-nerved  second  glume  and  5- 
nerved  lemma,  the  first  glume  and  the  palea  wanting,  the  stigmas 
long  and  slender. 

A  slender,  branching,  aquatic  grass,  probably  perennial,  the  leaves 
floating;  staminate  flowers  in  a  small  few-flowered  terminal  spike; 
pistillate  flowers  in  few-flowered  spikes  in  the  axils  of  the  leaves. 
Species  one,  in  the  southeastern  United  States. 

Type  species :  Hydrocliloa  carolincnsis  Beauv. 

Hydrocliloa  Beauv.,  Ess.  Agrost.  135,  pi.  24,  f.  4.  1812.  Beauvois  figures  one 
species,  which  he  names  H.  carolinensis.  The  species  was  first  described  as 
Zizania  flnitans  Michx.,  but  this  name  can  not  be  transferred  to  Hydrochloa 
because  of  H.  fluitans  Host. 

The  spikelets  of  each  sex  possess  but  two  bracts.  From  the  ap- 
pearance and  nervation  it  is  assumed  that  the  palea  is  present  in  the 
staminate  spikelets  and  wanting  in  the  pistillate. 

Ilydrochloa  ccvrolinensis  Beauv.  (fig.  127)  is  found  in  streams  and 
ponds  from  South  Carolina  to  Florida  and  Louisiana,  sometimes  in 
sufficient  abundance  to  become  troublesome.  It  has  no  economic  im- 
portance. 

Pharus  L.,  Syst.  Nat.,  ed.  10,  2: 1269.  1759.  A  tropical  American 
genus,  one  species  of  which,  P.  latifolius  L.,  was  included  by  Chap- 
man in  his  Flora  of  the  Southern  States.  The  locality  given  is 
"Orange  Lake,  Florida  (Herb.  Thurber)."  This  West  Indian  spe- 
cies has  not  been  observed  by  others  in  Florida  and  it  should  be 
credited  to  the  United  States  with  doubt. 

Rather  tall  monoecious  perennials,  with  broad  elliptic  or  oblanceo- 
late,  petiolate  blades  and  terminal  panicles,  the  large  terete  pistillate 
spikelets  appressed  along  the  rather  few  stiffly  spreading  branches, 


212  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 

these  disarticulating  at  the  base  and  easily  detached,  the  imcinate 
fruits  acting  like  burs. 


FIG.    126. — Luziola,  peruviana.      Plant,    X    i  ;    pistillate  and   staminate   spikelets,    X    5. 
11.  MELINIDEAE,  THE  MOLASSES-GRASS   TRIBE. 

Melinis  Beauv.,  Ess.  Agrost.  54,  pi.  11,  f.  4.     1812.     A  Brazilian 
genus.    Melinis  minutiflora  Beauv.  (molasses  grass)  is  cultivated  in 


GENERA  OF   GRASSES   OF   THE   UNITED   STATES. 


213 


the  Tropics  for  forage.  It  has  been  tried  in  the  warmer  parts  of  the 
South.  Molasses  grass  is  a  rather  stout  perennial,  with  viscid-pubes- 
cent foliage,  and  narrow  many-flowered  panicles  of  very  small 
awned  spikelets. 


FIG.  127.— Hydrochloa  carolinensis.     Plant,   X   \  ;  two  views  of  pistillate  spikelet,   X   5  ; 

stamina  te  spikelet,   X   5. 

12.  PANICEAE,  THE  MILLET  TRIBE. 

108.  ANTHAENANTIA  Beauv.1 

Spikelets  obovoid;  first  glume  wanting;  second  glume  and  sterile 
lemma  about  equal  in  length,  broad,  5 -nerved,  villous,  the  sterile 
lemma  with  a  small  palea  and  sometimes  with  a  staminate  flower; 
fertile  lemma  cartilaginous,  boat  shaped,  3-nerved,  subacute,  chest- 

1  For  a  discussion  of  this  and  the  following  genera  of  this  tribe,  see  Chase,  Proc.  Bioi. 
Soc.  Washington,  19:183-192,  1906;  21:1-10,  1908;  21:175-188,  1908;  24:103-160, 
1911. 


214  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


nut  brown,  as  long  as  the  glume,  the  pale  margins  very  narrow,  in- 
folding the  palea  its  entire  length. 

Perennial  erect  grasses  with  short 
creeping  rhizomes,  narrow,  firm,  flat 
blades,  the  uppermost  much  reduced,  and 
narrow  panicles,  the  slender  branches 
ascending  or  appressed.  Species  two,  on 
the  Coastal  Plain  of  the  southeastern 
United  States. 

Type  species:  Phalaris  rillosa  Michx. 
Anthaenaiitia  Beauv.,  Ess.  Agrost.  48,  pi.  10, 
f.  7.     1812.    Phalaris  villosa  is  the  only  species 
mentioned. 

Aulaxanthus  Ell.,  Bot.  S.  C.  and  Ga.  1:  102. 
1816.  Two  species  are  described,  A.  ciliatus  and 
A.  rufus.  The  first,  which 
is  the  same  as  Anthaenantia 
villosa,  is  accepted  as  the 
type. 

Aulaxia  Nutt,  Gen.  PI.  1: 
47.  1818.  Nuttall  changes 
Elliott's  name  Aulaxanthus 
to  Aulaxia. 

Anthaenantia  villosa 
(Michx.)  Beauv.  (fig. 
128),  with  comparatively 
short,  spreading  blades 
and  usually  pale  panicle, 
and  A.  rufa  (Ell.) 
Schult.,  with  long  erect 
blades  and  usually  pur- 
ple panicle,  are  of  no 
economic  importance. 


FIG.  128. — Anthaenantia  villosa.     Plant,   X   I  ;  spikelet  and  fertile  floret,   X   10. 
109.  VALOTA  Adans. 

Spikelets  lanceolate,  in  pairs,  short-pediceled,  in  two  rows  along 
one    side    of    a    narrow    rachis;    first    glume    minute,    glabrous; 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  215 

second  glume  and  sterile  lemma  about  as  long  as  the  fruit,  3  to 
5  nerved,  copiously  silky;  fertile  lemma  cartilaginous,  lanceolate, 
acuminate,  usually  brown,  the  flat  white  hyaline  margins  broad. 

Perennial  grasses,  the  slender  racemes  erect  or  nearly  so,  aggregate 
along  the  upper  part  of  the  main,  axis,  forming  a  white  or  brownish 
woolly  panicle.  Species  about  12,  in  the  warmer  parts  of  America 
and  in  Australia ;  3  species  in  the  southern  United  States. 

Type  species:  Andropogon  insularia  L. 

Valota  Adans.,  Fam.  PI.  2 :  495.  1763.  The  citation  given  by  Adanson  is  to 
"  Sloan,  t.  14.  f.  2."  which  is  also  given  by  Linnaeus  under  his  Andropogon  in- 
sularis,1  which  fixes  this  species  as  the  type. 

Trichachne  Nees,  Agrost.  Bras.  85.  1829.  Nees  describes  five  species,  the  first 
of  which,  T.  insularis,  based  on  Andropogon  insularis,  is  taken  as  the  type. 

Valota  is  closely  allied  to  Syntherisma,  differing  chiefly  in  the 
acuminate  fruit  and  the  silky  spikelets. 

Valota  insuldrls  (L.)  Chase  (Panicum  lanatwm  Rottb.,  P.  leuco- 
pJiaeum  H.  B.  K.)  (fig.  129),  common  in  the  American  Tropics,  with 
brown  or  tawny  inflorescence,  is  found  in  southern  Florida.  Valota 
hitchcockii  Chase,  with  short  blades  and  short-pubescent  spikelets  is 
a  rare  species  from  Texas  and  Mexico.  Valota  saccharata  (Buckl.) 
Chase  (Panicum  lachnanthum  Torr.),  with  copiously  long,  silky 
white  spikelets,  is  common  in  the  Southwestern  States  on  rocky  soil. 
The  first-mentioned  species  is  not  relished  by  cattle  and  in  the  West 
Indies  is  called  sour-grass.  'The  third  species  is  a  constituent  of  the 
ranges  of  the  Southwest,  but  furnishes  only  fair  forage. 

110.  SYNTHEKISMA  Walt.,  the  crab-grasses. 
(Digitaria  Hall.,  not  Heist.) 

Spikelets  solitary  or  in  twos  or  threes,  subsessile  or  short-pedi- 
celed,  alternate  in  two  rows  on  one  side  of  a  three-angled  winged  or 
wingless  rachis;  spikelets  lanceolate  or  elliptic,  plano-convex;  first 
glume  minute  or  wanting;  second  glume  equaling  the  sterile  lemma 
or  shorter ;  fertile  lemma  cartilaginous,  the  hyaline  margins  pale. 

Annual  or  sometimes  perennial,  erect  or  prostrate  grasses,  the  slen- 
der racemes  digitate  or  somewhat  scattered,  but  aggregate  along  the 
upper  part  of  the  culms.  Species  about  60,  in  the  warmer  parts  of  the 
world;  12  species  in  the  United  States,  mostly  in  the  southeastern 
part. 

Type  species :  Syntherisma  praecox  Walt. 

Digitaria  Hall.,  Stirp.  Helv.  2:  244,  1768,  not  Adans.,  1763,  nor  Heist.,  1759. 
Haller  describes  two  species.  No  specific  names  are  used,  but  the  first  species  is 
associable  by  citation  with . Panicum  sanguinale  L.  (Syntherisma  sanguinalis) 
••Mid  the  second  with  Panicum  dactylon  L.  (Capriola  dactylon}.  The  first  is 
chosen  as  the  type. 

Syntherisma  Walt.,  Fl.  Carol.  76.  1788.  Walter  describes  three  species,  8. 
praecox,  S.  serotina,  and  8.  villosa.  The  first  of  these  is  selected  as  the  typo. 
This  is  the  same  as  8,  sanguinalis. 

1  Syst.  Nat.,  ed.  10,  2:  1304.     1759. 


216  BULLETIN   772,   U.   S.   DEPARTMENT   OF   AGRICULTUREo 


FIG.  129. — Sour-grass,  Valota  insularis.     Plant,    X    i  ;  spikelet  and  fertile  floret,    X    10. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES. 


217 


Syntherisma  is  included  in  Panicum  by  some  botanists  and  in  Pas- 
palum  by  others.     It  differs  from  both  in  the  cartilaginous  rather 


than  indurate  fruit  and  in 
the  flat,  white,  hyaline 
margins  of  the  lemma. 

Our  commonest  species 
is  Syntherisma,  sanguincdis 
(L.)  Dulac  (Dig  it  aria 
sanguinalis  Scop.)  ( fig. 
130),  usually  called  crab- 
grass.  This  is  a  decumbent 
or  prostrate  annual,  usually 
more  or  less  purple,  with 
hispid  sheaths,  flat  blades, 
few  to  several  slender  digi- 
tate or  subdigitate  spikes 
or  racemes,  and  a  narrowly 
winged  rachis,  the  first 
glume  minute.  Crab-grass 
is  a  native  of  the  Old 
World,  but  is  now  widely 
distributed  in  tropical 
America,  and  is  common  in 
cultivated  soil  throughout 
the  eastern  and  southern 
part  of  the  United  States. 
It  is  often  a  bad  weed  in 
lawns.  In  the  Southern 
States,  where  crab-grass 
produces  an  abundant 
growth  in  the  late  summer 
on  the  fields  from  which 
crops  have  been  gathered, 

FIG.  130.— Crab-grass,  Syntherisma  sangwnaUs.     ft  is  utilized  for  forage  and 

"Plant-       V      1    •    -ftirrt    Trfck-wrc?    f\f    arvllr^lo-f    n-n/1     -P^-n-f -il^  ^ 


Plant,   X   \  ;  two  views  of  spikelet  and  fertile 
floret,   X   10. 


is  sometimes  cut  for  hay. 


218  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

Syntherisma  ischaemum  (Schrad.)  Nash  (Digitaria  humifusa 
Pers.,  Panicum  glabrum  Gaud.),  also  introduced,  is  darker  green  and 
glabrous,  and  has  dark  pubescent  spikelets,  the  first  glume  wanting. 
This  is  a  common  weed  in  lawns.  Syrtfherisma  fiUfo?*mis  (L.)  Nash 
is  an  erect  native  annual  with  erect  racemes,  the  rachis  not  winged. 
Several  other  species  are  found  in  Florida.  Nearly  all  the  species  of 
Syntherisma  are  weedy  grasses  or  tend  to  become  weeds. 

For  a  revision  of  the  species  of  Syntherisma  found  in  the  United 
States,  see  Nash,  Bull.  Torrey  Club  25:  289-303.  1898. 

111.  LEPTOLOMA  Chase. 

Spikelets  on  slender  pedicels;  first  glume  minute  or  obsolete;  sec- 
ond glume  3-nerved,  nearly  as  long  as  the  5  to  7  nerved  sterile  lemma, 
a  more  or  less  prominent  stripe  of  appressed  silky  hairs  down  the 
internerves  and  margins  of  each,  the  sterile  lemma  empty  or  inclos- 
ing a  minute  nerveless  rudimentary  palea;  fertile  lemma  cartilagi- 
nous, elliptic,  acute,  brown,  the  delicate  hyaline  margins  inclosing 
the  palea. 

Perennial  branching  grasses,  with  brittle  culms,  felty  pubescent 
at  base,  flat  blades,  and  open  or  diffuse  panicles,  these  breaking  away 
at  maturity,  becoming  tumbleweeds.  Species  four;  one  in  the  United 
States,  the  others  in  Australia. 

Type  species :  Panteum  cognatum  Schult. 

Leptoloma  Chase,  Proc.  Biol.  Soc.  Washington  19:  191.  1906.  The  type  is 
designated. 

The  only  species  found  in  our  country  is  Leptoloma  cognatum 
(Schult.)  Chase  (Panicum  autumnale  Bosc,  P.  divergens  Muhl.) 
(fig.  131)  growing  in  sandy  soil  from  New  England  to  Florida  ^and 
from  Minnesota  to  Texas.  This  genus  differs  from  Syntherisma 
chiefly  in  the  form  of  the  inflorescence,  being  an  open  panicle  rather 
than  an  aggregation  of  slender  spikes.  It  is  of  no  economic  impor- 
tance. 

112.  STENOTAPHRUM  Trin. 

Spikelets  embedded  in  one  side  of  an  enlarged  and  flattened  corky 
rachis  disarticulating  at  maturity,  the  spikelets  remaining  attached ; 
first  glume  small ;  second  glume  and  sterile  lemma  about  equal,  the 
latter  with  a  palea  or  staminate  flower ;  fertile  lemma  chartaceous. 

Creeping  stoloniferous  perennials,  with  short  flowering  stems, 
rather  broad  and  short  obtuse  blades,  and  terminal  and  axillary 
spikes.  Species  about  five ;  islands  of  the  Pacific ;  one  in  the  southern 
TJnited  States. 

Type  species :  Panicum  dimidiatum  L. 

Stenotaphrum  Trin.,  Fund.  Agrost.  175.  1820.  A  single  species  is  mentioned, 
8.  glabrum,  Trin.,  based  on  Rottboellia  dimidiata  L.,  which  in  turn  is  based  on 
Panicum  dimidiatum  L. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


219 


Our  species  is  Stenotaphrum  secimdatum  (Walt.)  Kuntze  (S. 
americanum  Schrank)  (fig.  132),  found  near  the  coast  from  North 
Carolina  to  Florida  and  Texas,  and  southward,  growing  especially 


FIG.  131. — Leptoloma  cognatum. 
Plant,  X  s  ;  two  views  of  spike- 
let  and  fertile  floret,  X  10. 


in  alluvial  or  mucky  soil.  It  is  culti- 
vated as  a  lawn  grass  in  the  coastal 
cities  under  the  name  of  St.  Augus- 
tine grass.  The  lawns  of  this  grass 
have  a  coarse  texture  but  are  other- 
wise satisfactory.  The  grass  is  prop- 
agated by  setting  out  cuttings  or 
pieces  of  the  stolons  bearing  shoots. 

113.  ERIOCHLOA  H.  B.  K. 

Spikelets  dorsally  compressed, 
more  or  less  pubescent,  solitary  or 
sometimes  in  pairs,  short-pediceled 
or  subsessile,  in  two  rows  on  one  side 
of  a  narrow,  usually  hairy  rachis, 
the  pedicels  often  clothed  with  long, 
stiff  hairs,  the  back  of  the  fertile 
lemma  turned  from  the  rachis;  lower 
rachilla  joint  thickened,  forming  a 
more  or  less  ringlike,  usually  dark- 
colored  callus  below  the  second 
glume,  the  first  glume  reduced  to  a 
minute  sheath  about  this  and  adnate 
to  it ;  second  glume  and  sterile  lemma 
about  equal,  acute  or  acuminate, 
the  lemma  usually  inclosing  a  hya- 
line palea  or  sometimes  a  stami- 


220  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


nate  flower;  fertile  lemma  indurate,  minutely  papillose-rugose, 
mucronate  or  awned,  the  awn  often  readily  deciduous,  the  mar- 
gins slightly  inrolled. 

Annual  or  perennial,  often 
branching  grasses,  with  termi- 
nal panicles  consisting  of  sev- 
eral or  many  spreading  or 
appressed  racemes,  usually 
rather  closely  arranged  along 
the  main  axis.  Species  about 
15,  in  the  warmer  parts  of  the 
world,  mostly  in  America;  6 
species  in  the  United  States,  in 
the  Southern  and  Southwest- 
ern States. 

Type  species:  EriocMoa  distachya 
H.  B.  K. 

Eriochloa  H.  B.  K.,  Nov.  Gen.  and 
Sp.  1 :  94,  pis.  30  and  31.  1816.  Two 
species  are  described,  E.  distachya 
and  E.  polystachya,  and  both  are 
figured.  The  first  is  chosen  as  the 
type. 

Helopus  Trin.,  Fund.  Agrost.  103, 
pi.  4.  1820.  The  only  species  men- 
tioned is  H.  pilosus,  which  is  the 


FIG.  132. — St.  Augustine  grass,  Stenotaphrum  secundatum.     Plant,    X    \  ;  two  views  of 
spikelet  and  fertile  floret,   X   10. 

same  as  Eriochloa  punctata.     Trinius  incorrectly  cites  Milium  ramosum  Retz. 
as  a  synonym  of  Helopus  pilosus. 

Oedipachne  Link,  Hort.  Berol.  1:  51.  1827.  The  only  species  mentioned  is 
Milium  punctatum  L.  (Eriochloa  punctata  (L.)  Hamilt),  upon  which  Oedi- 
pachne punctata  is  based. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  221 

Our  commonest  species  is  Eriochloa  acuminata  (Presl)  Kunth,  an 
annual,  1  to  2  feet  tall,  with  spikelets  about  5  mm.  long,  the  fertile 
lemma  apiculate.  This  is  found  from  Kansas  to  Texas  and  Arizona, 
in  open  ground,  often  a  weed  in  cultivated  soil.  In  some  books  this 
is  called  E.  polystachya  H.  B.  K.,  a  species  described  from  Ecuador. 
A  West  Indian  species,  E.  punctata  (L.)  Hamilt.  (fig.  133),  extends 
into  Louisiana  and  Texas. 

Our  species  appear  to  be  of  no  agricultural  importance.  One 
species  of  the  West  Indies  (E.  subglabra),  called  in  Porto  Rico 
malojilla,  is  used  for  forage.  This  has  been  tried  along  the  Gulf 
coast  from  Florida  to  southern  Texas,  and  has  given  excellent  results 
in  southern  Florida  and  at  Biloxi,  Miss.  Carib  grass,  as  it  is  pro- 
posed to  call  this  species,  is  similar  in  habit  to  Para  grass,  producing 
runners,  but  less  extensively,  and  is  suited  to  grazing  and  will 
furnish  a  good  quality  of  hay.  It  will  not  withstand  either  cold  or 
drought. 

114.  BEACHIABIA  (Trin.)  Griseb. 

Spikelets  dorsally  compressed,  solitary,  rarely  in  pairs,  subsessile, 
in  two  rows  on  one  side  of  a  3-angled,  sometimes  narrowly  winged 
rachis,  the  first  glume  turned  toward  the  axis;  first  glume  short  or 
nearly  as  long  as  the  spikelet ;  second  glume  and  sterile  lemma  about 
equal,  5  to  7  nerved,  the  lemma  inclosing  a  hyaline  palea  and  some- 
times a  staminate  flower;  fertile  lemma  indurate,  usually  papillose- 
rugose,  the  margins  inrolled,  the  apex  rarely  mucronate  or  bearing  a 
short  awn. 

Annual  or  perennial,, branching  and  spreading  grasses,  with  linear- 
blades  and  terminal  inflorescence  consisting  of  several  spreading  or 
appressed  racemes  along  a  common  axis.  Species  about  15,  in  the 
warmer  regions  of  both  hemispheres;  3  species  in  the  United 
States,  2  native  along  our  southern  border,  1  introduced. 

Type  species :  Panicum  erucaeforme  J.  E.  Smith. 

Brachiaria  Griseb.,  in  Ledeb.  Fl.  Ross.  4:  469.  1853.  Only  one  species  is 
mentioned,  B.  crucaeformis. 

From  those  species  of  Panicum  with  spikelets  in  one-sided  spike- 
like  racemes,  this  genus  differs  in  having  the  spikelets  in  the  reverse 
position  relative  to  the  rachis,  that  is,  with  the  first  glume  toward  the 
rachis. 

The  three  species,  none  of  which  has  economic  importance,  are 
Brachiaria  erucaeformis  (J.  E.  Smith)  Griseb.,  an  annual,  with 
pubescent  spikelets,  occasionally  introduced  from  Europe,  B.  platy- 
phylla  (Griseb.)  Nash  (fig.  134),  an  annual,  with  glabrous  spikelets, 
growing  in  Louisiana  and  Texas,  and  B.  ciliatissima  (Buckl.)  Chase 
(Panicum  ciliatissimwm  Buckl.),  a  perennial,  with  silky  spikelets, 
growing  in  Arkansas  and  Texas, 


222  BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 


FIG.  133. — Eriochloa  punctata.   Plant,   X   h  ',  two  views  of  spikelet  and  fertile  floret,  X  10. 


GENERA  OF   GRASSES  OF  THE  UNITED  STATES. 


223 


115.  AXONOPUS    Beauv. 
(Anastrophus  Schlecht.) 

Spikelets  depressed  biconvex,  not  turgid,  oblong,  usually  obtuse, 
solitary,  sessile,  and  alternate,  in  two  rows  on  one  side  of  a  3-angled 

rachis,  the  back  of  the  fertile  lemma  turned 
from  the  axis ;  first  glume  wanting ;  second 
glume  and  sterile  lemma  equal,  the  lemma 
without  a  palea;  fertile  lemma  and  palea 
indurate,  the  lemma  oblong-elliptic,  usually 
obtuse,  the  margins  slightly  inrolled. 

Stoloniferous  or  tufted  perennials,  rarely 
annuals,  with  usually  flat  or  folded,  ab- 
ruptly rounded  or.somewhat  pointed  blades, 
and   few   or   numerous,   slender,   spikelike 
racemes,    digitate   or   racemose   along   the 
main    axis.      Species    about    30,    tropical 
America,    1    or    2    introduced    into    the 
Tropics  of  the  Old  World;   2  species  in 
the  United   States,  in  moist 
soil   in   the    Southeastern 
States. 

Type  species:  Milium  compres- 
sitm  Swartz. 

Axonopus  Beauv.,  Ess.  Agrost. 
12, 154.  1812.  Beauvois  mentions 
several  diverse  species  that  be- 
long to  his  new  genus,  the  first 
being  Milium  compressum,  which 


FIG.  134. — Brachiaria  platyphulla.     Plant,   X   \  ;  two  views  of  spikelet  and  fertile  floret, 

X    10. 


224  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

is  chosen  as  the  type,  since  it  is  the  only  species  that  agrees  with  his  de- 
scription of  the  genus  in  having  solitary  spikelets.  The  other  species 

that  he  mentions  are  now  referred  to  other  genera, 
Milium  digitatum  to  Syntherisma,  M.  cimicinum  to 
Coridochloa,  M.  paniceum  to  Syntherisma.  In  a 
subsequent  paragraph  the  author  briefly  describes 
a  new  species,  A.  aureus,  which  he  thinks  ought 
to  belong  to  this  genus.  Nash  1  selects  A.  aureus 
as  the  type  of  Axonopus. 

Cabrera  Lag.,  Gen.  and  Sp.  Nov.  5.  1816.  The 
type  is  C.  chrysoblepharis  Lag.,  the  only  species 
mentioned.  To  this  group  belongs  Axonopus  aureus 
mentioned  above. 

Anastrophus  Schlecht.,  Bot.  Zeit.  8:  681.  1850. 
The  type  is  Paspalum  platyculmum  Du  Petit-Thou., 
the  first  of  several  species  referred  to  the  genus. 
This  is  probably  the  same  as  Axonopus  compressus, 
or  at  least  closely  allied  to  that  species. 

Lappagopsis  Steud.,  Syn.  PI.  Glum.  1 :  112.  1854. 
The  type  is  L.  bijuga  Steud.,  the  only  species  de- 
scribed. 

The  most  important  species  of  the  genus 
in  the  United  States  is  Axonopus  compres- 
sus (Swartz)  Beauv.  (fig.  135), 
usually  called  carpet  grass  in  the 
South.  This  is  a  stolonif  erous  per- 
ennial, with  compressed  stems, 
comparatively  short,  flat,  broadly 
linear,  abruptly  pointed  blades, 
and  slender  spikes  somewhat  digi- 
tate at  the  summit  of  the  culms. 
Carpet  grass  is  common  in  the 
Tropics  and  extends  in  the  United 
States  from  Virginia  to  Florida 
and  Texas  in  the  lowland  along 
the  coast.  It  thrives  particularly 
in  alluvial  or  mucky  open  ground, 
where  it  becomes  the  dominant 


FIG.  135. — Carpet  grass,  Axonopus  compressus.     Plant,    X    \  ;  two  views  of  spikelet  and 

fertile  floret,   X  10. 

grass.  Carpet  grass  is  the  predominant  pasture  grass  in  the  region 
mentioned,  but  is  of  little  importance  on  sandy  soil  and  does  not  thrive 
on  the  uplands.  In  the  region  where  it  thrives  as  a  pasture  grass 


Amer.  Fl.  17:  165.     1912. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  225 

it  may  be  utilized  as  a  lawn  grass.  For  this  purpose  it  is  propa- 
gated by  setting  out  pieces  of  the  stolons.  It  soon  spreads  and 
occupies  the  space  between. 

A  second  species  of  the  genus,  A.  fwrcatus  (Fliigge)  Hitchc.,  is 
found  over  about  the  same  range  as  the  preceding,  but  confined  to 
the  United  States.  This  is  infrequent  and  is  usually  of  no  economic 
importance,  but  is  a  valuable  pasture  grass  in  the  Kissimmee  region, 
Fla.  It  is  distinguished  by  its  larger  spikelets,  4  to  6  mm.  long. 

116.  REIMAROCHLOA  Hitchc. 
(Reimaria  of  authors.) 

Spikelets  strongly  dorsally  compressed,  lanceolate,  acuminate, 
rather  distant,  subsessile,  and  alternate  in  two  rows  along  one  side 
of  a  narrow,  flattened  rachis,  the  back  of  the  fertile  lemma  turned 
toward  it;  both  glumes  wanting,  or  the  second  sometimes  present  in 
the  terminal  spikelet;  sterile  lemma  about  equaling  the  fruit,  the 
sterile  palea  obsolete ;  fertile  lemma  scarcely  indurate,  faintly  nerved, 
acuminate,  the  margins  inrolled  at  the  base  only,  the  palea  free  nearly 
half  its  length. 

Spreading  or  stoloniferous  perennials,  with  flat  blades  and  slender 
spikes,  these  subdigitate  or  racemose  along  the  upper  part  of  the  culm, 
stiffly  spreading  or  reflexed  at  maturity.  Species  about  four;  in  the 
American  Tropics,  one  extending  into  Florida. 

Type  species :  Reimaria  acuta  Fliigge. 

Reimarochloa  Hitchc.,  Contr.  U.  S.  Nat.  Herb.  12:  198.  1909.  The  type  is 
designated.  The  genus  includes  most  of  the  species  that  have  been  assigned  to 
Reimaria  Fliigge,  the  type  of  which  is  R.  Candida,  a  species  of  Paspalum. 

Only  one  species  is  found  in  the  United  States,  Reimarochloa 
oligostacJiya  (Munro)  Hitchc.  (fig.  136),  confined  to  Florida  and 
Cuba.  It  has  no  economic  importance. 

117.  PASPALUM  L. 

Spikelets  plano-convex,  usually  obtuse,  subsessile,  solitary  or  in 
pairs,  in  two  rows  on  one  side  of  a  narrow  or  dilated  rachis,  the  back 
of  the  fertile  lemma  toward  it;  first  glume  usually  wanting;  second 
glume  and  sterile  lemma  commonly  about  equal,  the  former  rarely 
wanting;  fertile  lemma  usually  obtuse,  chartaceous-indurate,  the 
margins  inrolled. 

Mostly  perennials,  with  one  to  many  spikelike  racemes,  these  single 
or  paired  at  the  summit  of  the  culms  or  racemosely  arranged  along 
the  main  axis.  Species  numerous,  probably  as  many  as  200,  widely 
distributed  in  the  warmer  parts  of  both  hemispheres;  about  50  spe- 
cies in  the  United  States,  mostly  in  the  Southeastern  States. 

Type  species:  Paspalum  dimidiatum  L. 

Paspalum  L.,  Syst.  Nat.  ed.  10,  2:  855,  1759.  Four  species  are  described,  P.  di- 
midiatum (of  which  "  Panicum  dissectum  sp.  pi.  57  n,  (? "  is  cited  as,  a  syno- 

97769°— 19— Bull.  772 15 


226          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


nym),  P.  virgatum,  P.  paniculatum,  and  P.  distichum.    The  first  is  selected  as 
the  type.    All  are  still  retained  in  the  genus. 


FIG.    136. — Reimarochloa  oligostachya.      Plant    X    I  ;   two   views  of  spikelet  and   fertile 

floret,    X    10. 

Ceresia  Pers.,  Syn.  PI.  1 : 85.  1805.  A  single  species,  C.  elegans  Pers.,  is 
included.  This  is  one  of  the  species  having  a  broad-winged  rachis. 

Reimaria  Fliigge,  Gram.  Monogr.  213.  1810.  Three  species  are  included, 
R.  Candida  Humh.  and  Bonpl.,  .R.  elepans,  and  R.  acuta*  The  first  two  are 


GENEKA  OF  GRASSES  OF  THE  UNITED  STATES.  227 

species  of  Paspalum  in  which  both  glumes  are  wanting,  the  third,  to  which  the 
generic  description  less  aptly  applies,  is  a  species  of  Reimarochloa.  Reimaria 
Candida  is  taken  as  the  type. 

Cymatochloa  Schlecht,  Bot.  Zeit.  12 :  817,  821.  1854.  Two  names,  "  C.  fluir 
tans  (Ceresia  fluitaus  Ell.)"  and  "  C.  repens  (Paspalum  repens  Berg.)"  are 
given.  Both  names  apply  to  the  same  species,  Paspalum  repens  Berg. 

Dimorphostachys  Fourn.,  Compt  Rend.  Acad.  Sci.  (Paris)  80:  441.  1875. 
The  type  is  Panicum  monostachyum  H.  B.  K.,  the  first  of  four  species  men- 
tioned. 

Paspalum  is  closely  allied  to  Panicum,  differing  chiefly  in  the 
strictly  racemose  inflorescence  and  the  plano-convex  spikelets  in 
which  the  first  glume  is  wanting.  In  a  few  species  (section  Dimor- 
phostachys, in  Paspalum  distichum  and  in  P.  bifidum  (Bertol.) 
Nash)  the  first  glume  is  present  on  at  least  a  part  of  the  spikelets. 
In  P.  pulchellum  Kunth  of  tropical  America  and  a  few  other  species 
both  glumes  are  wanting. 

In  spite  of  the  large  number  of  species  in  this  genus,  very  few 
are  of  economic  importance.  Most  of  the  species  make  a  sparse 
growth  in  moist  pine  barrens  and  old  fields  and  are  not  grazed  to 
any  extent.  A  few  species  inhabiting  meadows  and  savannas  fur- 
nish a  limited  amount  of  forage.  Among  these  may  be  mentioned 
P.  laeve  Michx.  (fig.  137)  and  P.  ciliatifolium  Michx.,  and  the  allies 
of  these  species.  Paspalum  laeve,  with  2  or  3  racemes  and  spikelets 
2.5  mm.  long,  is  common  from  Maryland  to  Florida  and  Texas. 
Paspalum  ciliatifolium  and  its  allies,  besides  the  one  to  few  slender 
racemes  on  the  main  culm,  have  several  naked  branches  from  the 
upper  sheaths,  each  branch  usually  bearing  a  single  raceme. 

Paspalum  distichum  L.,  with  creeping  stolons  and  racemes  in 
pairs  at  the  summit  of  the  culms,  is  widely  distributed  along  muddy 
coasts  and  ditch  banks  from  Virginia  to  Florida  and  thence  across 
the  continent  to  California  and  Washington.  Where  abundant  it 
furnishes  some  forage. 

Paspalum  dilatatum  Poir.  has  been  tried  as  a  forage  grass  in  the 
Southern  States,  where  it  has  been  cultivated  under  the  name  of 
water  grass.  It  has  little  to  recommend  it  here,  but  in  the  Hawaiian 
Islands  it  gives  much  promise  as  a  pasture  grass.  In  tropical  Amer- 
ica species  of  Paspalum  form  an  important  element  in  the  grazing 
land  of  the  savannas,  P.  notatum  Fliigge  being  one  of  the  most 
abundant. 

118.  PANICUM  L. 

Spikelets  more  or  less  compressed  dorsiventrally,  arranged  in  open 
or  compact  panicles,  rarely  racemes;  glumes  2,  herbaceous,  nerved, 
usually  very  unequal,  the  first  often  minute,  the  second  typically 
equaling  the  sterile  lemma,  the  latter  of  the  same  texture  and  simu- 
lating a  third  glume,  bearing  in  its  axil  a  membranaceous  or  hyaline 
palea  and  sometimes  a  staminate  flower,  the  palea  rarely  wanting; 


228  BULLETIN"   772,   TJ.   S.   DEPARTMENT  OF  AGRICULTURE. 

fertile   lemma   chartaceous- indurate,  typically    obtuse,   the     nerves 
obsolete,  the  margins  inrolled  over  an  inclosed  palea  of  the  same  tex- 


FIG.  137. — Paspalum  laeve.     Plant,   X    \  ;  two  views  of  spikelet  and  fertile  floret,    X    10. 

ture,  a  lunate  line  of  thinner  texture  at  the  back  just  above  the  base, 
the  rootlet  protruding  through  this  at  germination. 


GENERA  OF   GRASSES   OF   THE  UNITED  STATES.  229 

Annual  or  perennial  grasses,  of  various  habit.  Species  probably 
about  500,  mostly  confined  to  the  warmer  regions  of  both  hemi- 
spheres, about  150  species  being  found  in  the  United  States. 

Type  species :  Panicum  miliaceum  L. 

Panicum  L.,  Sp.  PI.  55,  1753 ;  Gen.  PI.,  ed.  5,  29.  1754.  Twenty  species  are 
described.  The  first  ten  and  the  fifteenth  are  now  referred  to  other  genera.  Of 
the  species  considered  typical  by  Linnaeus,  as  indicated  by  the  description  in 
his  Genera  Plantarum,  Panicum  miliaceum  is  the  only  one  cultivated  and  is 
therefore  chosen  as  the  type.1 

Eatonia  Raf.,  Journ.  de  Phys.  89:  104.  1819.  A  single  species,  E.  purpura- 
scens,  which  is  the  same  as  Panicum  virgatum,  is  included. 

Steinchisma  Hal,  Bull.  Bot.  Seringe  1 :  220.  1830.  "  Panicum  divaricatum,  P. 
hians  "  are  cited,  both  names  applying  to  the  same  species,  P.  Mans  Ell. 

Phanopyrum  (Raf.)  Nash,  in  Small,  Fl.  Southeast.  U.  S.  104.  1903.  Based 
on  "  Panicum,  subgenus  Phanopyrum  Raf.,"  with  a  single  species,  P.  gymnocar- 
pon  (Ell.)  Nash. 

Chasea  Nleuwl.,  Amer.  Midi.  Nat.  2:  64.  1911.  A  new  name  proposed  for 
"  Panicum  of  the  authors  not  of  Linnaeus  or  only  in  part,"  the  name  Panicum 
being  applied  to  Chaetochloa. 

Among  the  species  of  the  United  States  two  subgenera  are  recog- 
nized, besides  Panicum  proper. 

Subgenus  Paurochaetium  Hitchc.  and  Chase.  Perennials  with 
tufted  culms,  erect  narrow  blades,  narrow,  more  or  less  spikelike 
inflorescence,  the  ultimate  branchlets  produced  beyond  the  uppermost 
spikelets  as  a  bristle  1  to  6  mm.  long,  the  apiculate  fruits  transversely 
rugose.  There  are  four  species  within  our  limits,  one  from  Florida, 
three  from  Texas.  This  subgenus  shows  a  transition  to  Chaetochloa. 

Subgenus  Dichanthelium  Hitchc.  and  Chase.  Perennials  forming 
a  usually  well-marked  rosette  of  winter  leaves,  having  a  vernal  phase 
of  simple  culms  and  terminal  panicles  of  small,  perfect,  but  usually 
sterile  spikelets,  and  an  autumnal  phase  produced  by  the  branching 
of  the  culms  after  the  maturity  of  the  primary  panicles,  the  sec- 
ondary leaves  and  panicles  usually  much  reduced,  the  spikelets  cleis- 
togamous  and  fruitful,  sometimes  hidden  in  the  sheaths.  There  are 
105  species  within  our  limits,  the  species  being  especially  abundant 
on  the  Atlantic  Coastal  Plain.  A  representative  of  this  subgenus  is 
Panicum  dichotomum  L.  (fig.  138).  A  common  species  in  the  East- 
ern States  is  P.  clandestinum  L.  (PI.  XVII),  one  of  the  most  robust 
representatives  of  the  group.  This  has  bristly  sheaths  and  cordate 
clasping  blades  as  much  as  an  inch  wide.  It  grows  in  moist  soil  and 
furnishes  a  moderate  amount  of  forage. 

The  remaining  species  belong  for  the  most  part  to  true  Pani- 
cum, called  by  some  the  subgenus  Eupanicum.  The  more  important 
of  these  are  the  following:  Panicum  barbinode  Trin.,  Para  grass,  a 
perennial  with  stout  stolons  as  much  as  15  feet  long,  culms  3  to  6  feet 
tall  from  a  creeping  base,  bearded  nodes,  and  panicles  4  to  6  inches 
long,  consisting  of  several  spikelike  racemes  of  glabrous  spikelets 

1  For  a  full  discussion  of  the  type  species  of  Panicum,  see  Hitchcock  and  Chase,  Contr. 
U.  S.  Nat.  Herb.  15:  13.  1910. 


230 


BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


3  mm.  long.     It  is  com- 
monly cultivated  in  tropi- 
cal   America    for    forage 
and  has  been  introduced 
for  this  purpose  in  Flor- 
ida  and   southern   Texas 
and  also  into  the  Tropics 
of  the   Old   World.     In 
Porto    Rico    it    is    called 
malojilla.      This    species 
has   been   incorrectly   re- 
ferred to  P.  molle  Swartz. 
A    field    of    Para    grass 
soon  becomes  a  tangle  of 
stolons  and  the  decumbent 
bases  of  the  stems,  and  for  best  results  it 
must  be  renewed  by  plowing  or  disking. 
Panicum  maximum  Jacq.,  guinea  grass, 
is  a  perennial  erect  bunch-grass,  4  to  6 
feet  tall,  with  open  spreading  panicles 
of  elliptic  spikelets  about  3  mm.  long, 
the  fruit  rugose.     This  is  a  native  of 
Africa,  introduced  into  tropical  America, 
where  it  is  cultivated  for  forage,  fur- 
nishing pasture  and  green  feed.     It  is 
said  to  have  been  introduced  into  Ja- 
maica from  west  tropical  Africa  in  1774. 
These  two  species,  Para  grass  and  guinea 
grass  are  the  only  grasses  that  are  ex- 

FIG.    138.  —  Panicum   dicJwto-     tensively  cultivated  for  forage  in  tropi- 
mum.     Plant,    x    i ;    two     cal   America.     Panicum  miliaceum  L., 

views   of  spikelet  and  fertile  -11    j.       i  -n    ^       i 

floret,  x  10.  proso    millet,    broom-corn    millet,    hog 

millet,  an  erect  annual  2  to  3  feet  tall, 

with  a  drooping  panicle,  is  cultivated  in  Europe  for  the  seed,  which 
is  used  for  food.  It  is  sparingly  cultivated  in  this  country  for  forage. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XVII, 


PANICUM  CLANDESTINUM. 

Common  in  moist  woods.    Useful  for  forage  and  for  ornament. 


Bui.  772,  U.  S.  Dept.  of  Agriculture 


PLATE  XVIII, 


EULALIA    (MlSCANTHUS   SINENSIS).       GROWN    FOR    ORNAMENT 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES. 


231 


Panicum  virgatum  L.  (fig.  139)  switch-grass,  an  erect  perennial  3  to 
5  feet  tall,  with  open  spreading  panicle,  is  common  in  the  eastern  half 


Fio.   139. — Switch-grass,   Panicum  virgaiwm.     Plant,    X    I ;   two  views  of  spikelet  and 

fertile  floret,    X    10. 

of  the  United  States.    It  is  a  constituent  of  prairie  hay.    Panicum 
bulbosum  H.  B.  K.,  of  the  Southwest  develops  well-marked  corms 


232  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

at  the  base  of  the  culms.  Panicum  texanum  Buckl.,  Texas  millet, 
Colorado  grass,  is  an  annual  rather  weedy  grass  of  Texas  that  has 
been  utilized  for  hay.  It  has  been  called  Colorado  grass  because  it 
grows  in  the  valley  of  the  Colorado  River.  Panicwn  dichotomi- 
florum  Michx.  is  a  smooth,  annual,  much-branched,  rather  succulent 
weed,  common  in  the  eastern  United  States  in  the  autumn.  The 
first  glume  is  very  short  and  truncate.  Panicum  capillare  L.  (fig. 
140),  old- witch  grass,  is  an  annual  weed,  with  hirsute  sheaths  and  a 
relatively  large  open  capillary  panicle  with  small  spikelets.  At 
maturity  the  panicle  breaks  away  and  is  blown  about  by  the  wind 
as  a  tumble  grass.  Panicum  geminatum  Forsk.  (fig.  141),  a  common 
tropical  species,  extends  into  Florida  and  Texas. 

Besides  the  two  subgenera  there  are  a  few  species  that  can  not  be 
included  in  true  Panicum.  Two  of  these  within  our  range  are  of 
some  importance.  Panicum  obtuswn  H.  B.  K.  (fig.  142),  a  forage 
grass  of  the  Southwest,  producing  long  wiry  stolons  with  bearded, 
swollen  nodes,  and  short,  erect,  fertile  culms  with  narrow  panicles  of 
obtuse  spikelets,  is  called  grapevine  mesquite,  because  of  the  long, 
tough  stolons,  and  adobe  grass,  because  it  is  found  on  slightly  alka- 
line soil.  This  species  differs  from  Eupanicum  in  the  long  first 
glume  and  the  racemose  branches  of  the  inflorescence.  Panicum 
kemitomon  Schult.,  maiden  cane,  is  found  in  moist  soil,  often  in 
the  water,  from  Texas  to  Florida  and  Delaware  near  the  coast.  It 
produces  extensively  creeping  rhizomes  and  numerous  sterile  shoots. 
The  panicle  is  narrow,  with  short  appressed  branches.  On  account 
of  the  rhizomes  it  becomes  a  troublesome  weed  in  cultivated  soil, 
especially  in  Florida.  This  species  differs  from  Eupanicum  in  the 
less  chartaceous  fruit  with  the  palea  free  at  the  tip.  The  seeds  of 
Panicum  sonorum  Beal  are  used  for  food  by  the  Cocopa  Indians. 

See  Williams,  U.  S.  Dept.  Agr.,  Farmers'  Bull.  101,  1899;  Scrib- 
ner,  U.  S.  Dept.  Agr.,  Div.  Agrost.  Bull.  20,  fig.  23,  1900;  Hitch- 
cock and  Chase,  Contr.  U.  S.  Nat.  Herb.  15,  1910.  The  last  work 
is  a  revision  of  the  genus  Panicum  in  North  America  and  gives  full 
descriptions  and  synonymy  of  all  the  species. 

119.  LASIACIS   (Griseb.)   Hitchc. 

Spikelets  subglobose,  placed  obliquely  on  their  pedicels ;  first  glume 
broad,  somewhat  inflated-ventricose,  usually  not  over  one-third  the 
length  of  the  spikelet,  several-nerved;  second  glume  and  sterile 
lemma  about  equal,  broad,  abruptly  apiculate,  papery-chartaceous, 
shining,  many-nerved,  glabrous,  or  lanose  at  the  apex  only,  the  lemma 
inclosing  a  membranaceous  palea  and  sometimes  a  staminate  flower ; 
fertile  lemma  white,  bony-indurate,  obovoid,  obtuse,  this  and  the 
palea  of  the  same  texture,  bearing  at  the  apex  in  a  slight  crateriform 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES.  233 


FIG.  140. — Old-witch  grass,  Panicum  capillcwe.     Plant,   X    I  ;  two  views  of  spikelet  and 

fertile  floret,    X    10. 


234  BULLETIN   7*72,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 

depression  a  tuft  of  woolly  hairs,  the  palea  concave  below,  gibbous 
above,  the  apex  often  free  at  maturity. 


FIG.   141. — Panicum  geminatum.     Plant,    X    i  ;  two  views  of  spikelet  and  fertile  floret 

X   10. 

Large  branching  perennials,  with  woody  culms  often  clambering 
several  feet  high  into  shrubs  or  trees,  the  blades  firm,  flat,  usually 


GENERA  OF  GRASSES  OF  THE  UNITED  STATES.  235 

lanceolate  and  narrowed  into  a  petiole,  the  spikelets  in  an  open 
panicle.  Species  about  20;  in  the  American  Tropics,  one  extending 
into  southern  Florida. 


FIG.    142. — Grapevine   mesquite,   Panicum    obtusum.      Plant,    X    I  \    spikelet   and   fertile 

floret,   X    10. 


236  BULLETIN  772,  TJ.   S.   DEPARTMENT  OF  AGRICULTURE. 


Type  species:  Panicum  divaricatum  L. 
Panicum,  section  Lasiacis  Griseb,  Fl.  Brit.  W.  Ind.  551. 
included,  the  first  of  which  is  P.  divaricalum. 

Lasiacis  Hitchc.,  Contr.  U.  S.  Nat.  Herb.  15 : 16. 


1864.     Five  species 


1910.  The  type  is  desig- 
nated. This  genus  was  previously 
included  as  a  section  in  Panicum, 
from  which  it  differs  in  habit,  the 
woody  culms  resembling  those  of 
bamboos,  and  in  the  oblique  spike- 
lets  with  the  woolly  apex  of  the 
fruit  and  the  gibbous  fertile  palea. 

The  only  species  in  the 
United  States  is  Lasiacis  dr- 
varicata  (L.)  Hitchc.  (fig. 
143)  of  southern  Florida.  It 
has  no  economic  value. 

120.  SACCIOLEPIS  Nash. 

Spikelets  oblong-conic ; 
first  glume  small,  much 
shorter  than  the  spikelet ;  sec- 
ond glume  broad,  inflated- 


FIG.  143. — Lasiaois  divaricata.     Fascicle  of  branches, 
X    1;  spikelet  and -fertile  floret,    X    10. 


saccate,  strongly  many-nerved;  sterile  lemma  narrower,  flat,  fewer 
nerved,  its  palea  nearly  as  long,  often  subtending  a  staminate  flower ; 
fertile  lemma  stipitate,  elliptic,  chartaceous-indurate,  the  margins  in- 
rolled,  the  palea  not  inclosed  at  the  summit. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


237 


Annuals  or  perennials,  of  wet  soil,  usually  branching,  the  inflores- 
cence a  dense,  usually  elongate,  spikelike  panicle.     Species   about 

12;  in  the  Tropics  of  both  hemi- 
spheres, 1  extending  into  the  south- 
eastern United  States. 

Type  species:  Panicum  gibbum  Ell. 
Sacciolepis  Nash,  in  Britton,  Man.  80. 
1901.    Only  one  species  is  described. 

Sacciolepis  striata  (L.)  Nash 
(Holcus  striatm  L.,  Panicum.  gib- 
bum  Ell.)  (fig.  144)  is  a  stolonifer- 
ous  marsh  grass  found  from  Vir- 
ginia to  Oklahoma  and  southward. 
It  has  no  economic  value. 

121.    OPLISMENUS  Beauv. 

Spikelets  terete  or  somewhat  lat- 
erally compressed,  subsessile,  soli- 
tary or  in  pairs,  in  two  rows 
crowded  or  approximate  on 
one  side  of  a  narrow  scabrous 
or  hairy  rachis;  glumes 
about  equal,  emarginate  or 
2-lobed,  awned  from  between 
the  lobes;  sterile  lemma  ex- 
ceeding the  glumes  and  fruit, 
notched  or  entire,  mucronate 


FIG.   144. — Sacciolepis  striata.     Plant,    X    J  ;   two  views  of  spikelet  and   fertile  floret, 

X    10. 

or  short-awned,  inclosing  a  hyaline  palea ;  fertile  lemma  elliptic,  acute, 
convex  or  boat  shaped,  the  firm  margins  clasping  the  palea,  not  inrolled. 


238          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

Freely  branching,  creeping,  shade-loving  annuals  or  perennials, 
with  erect  flowering  shoots,  flat,  thin  lanceolate  or  ovate  blades,  and 
several  one-sided,  thickish,  short  spikes  rather  distant  on  a  main  axis. 
Species  about  10,  in  the  Tropics  of  both  hemispheres,  1  extending 
into  the  Southern  States. 

Type  species:  Oplismenus  africanus  Beauv. 

Oplismenus  Beauv.,  Fl.  Owar.  2:  14,  pi.  58,  f.  1.  1809.  A  single  species  is 
described. 

Orthopogon  R.  Br.,  Prodr.  Nov.  Holl.  194.  1810.  Four  species  are  described, 
O.  compositus,  O.  aemulus,  O.  flaccidus,  and  O.  imbecillis.  Panicum  compositum 
L.  is  chosen  as  the  type,  this  being  the  basis  of  the  first  species  of  Orthopogon. 

The  only  species  in  the  United  States  is  Oplismenus  setarius 
(Lam.)  Roem.  and  Schult.  (fig.  145),  found  in  shady  places  from 
Florida  to  Texas.  This  is  grazed  by  stock,  but  is  not  sufficiently 
abundant  to  be  of  importance. 

122.  ECHINOCHLOA  Beauv. 

Spikelets  plano-convex,  often  stiffly  hispid,  subsessile,  solitary  or 
in  irregular  clusters  on  one  side  of  the  panicle  branches;  first  glume 
about  half  the  length  of  the  spikelet,  pointed ;  second  glume  and  sterile 
lemma  equal,  pointed,  mucronate,  or  the  glume  short-awned  and  the 
lemma  long-awned,  sometimes  conspicuously  so,  inclosing  a  mem- 
branaceous  palea  and  sometimes  a  staminate  flower;  fertile  lemma 
plano-convex,  smooth  and  shining,  acuminate-pointed,  the  margins 
inrolled  below,  flat  above,  the  apex  of  the  palea  not  inclosed. 

Coarse,  often  succulent,  annual,  or  sometimes  perennial,  grasses, 
with  compressed  sheaths,  linear  flat  blades,  and  rather  compact  pani- 
cles composed  of  short,  densely  flowered  racemes  along  a  main  axis. 
Species  about  10,  in  the  warm  and  temperate  regions  of  both  hemi- 
spheres ;  4  species  in  the  United  States. 

Type  species :  Panicum  crusgalli  L. 

Echinochloa  Beauv.,  Ess.  Agrost.  53,  pi.  11,  f.  2.  1812.  The  species  figured  is 
selected  as  the  type. 

With  the  exception  of  E  chmochloa  colonum  (L.)  Link,  the  species 
of  Echinochloa  have  distinctly  awned  or  awn-pointed  spikelets.  In 
that  cosmopolitan  species  the  spikelets  are  merely  apiculate  or  mucro- 
nate, and  the  racemes  are  simple  and  rather  remote. 

Echinochloa  CTUsgdlli  (L.)  Beauv.  (fig.  146),  barnyard  grass,  is 
a  common  weedy  annual  found  throughout  the  country  except  at 
higher  altitudes.  The  panicles  vary  much  in  the  size  and  length  of 
the  awns,  and  in  color  vary  from  green  to  dark  purple.  In  fields  and 
waste  places  the  plants  are  usually  spreading,  but  in  water  or  wet 
places  may  be  stout  and  erect.  An  erect  short-awned  form,  with 
short,  ascending  racemes,  found  in  the  Southwestern  States,  is  the 
Mexican  E.  crusgalli  zelayensis  (H.  B.  K.)  Hitchc.  (Oplismenus 
zelayensis  H.  B.  K.).  E.  crusgalli  edulis  (Panicum  frumentaceum 
Koxb.,  1820,  not  Salisb.,  1796)  is  a  form  that  has  been  cultivated  in 


GENERA  OF   GRASSES   OF   THE   UNITED   STATES.  'Jo 9 

tropical  Asia  for  the  seeds,  which  are  used  for  food.  It  differs  in 
having  short,  compact,  appressed,  somewhat  incurved  racemes  and 
nearly  awnless  spikelets.  This  form  has  been  advertised  by  seeds- 


FIG.   145. — Oplismenus  setarius.     Plant,    X    J  ;  two  views  of  spikelet  and  fertile  floret, 

X  10. 

men  in  this  country  as  billion-dollar  grass  and  recommended  for 
forage.  It  has  some  forage  value,  but  requires  considerable  moisture 
to  produce  abundantly,  and  is  rather  too  succulent  to  make  good  hay. 


240  BULLETIN   772,   U.    S.   DEPARTMENT   OF  AGRICULTURE. 


In  these  forms  the  sheaths  are  smooth.  Echinochloa  walteri  (Pursh) 
Heller  is  a  closely  allied  native  species  with  hirsute  sheaths  and  long- 
awned  spikelets. 

All  the  species  of  Echinochloa  are 
grazed  by  horses  and  cattle,  but 
usually  grow  in  situations  where  they 
can  not  well  be  utilized. 


FIG.  146. — Barnyard  grass,  Echinochloa  crusgalll.     Plant, 

and  fertile  floret,   X   10. 


two  views  of  spikelet 


GENERA  OF  GRASSES   OF  THE   UNITED  STATES.  241 

123.  TRICHOLAENA  Schrad. 

Spikelets  on  short  capillary  pedicels;  first  glume  small,  much 
shorter  than  the  spikelet,  villous;  second  glume  and  sterile  lemma 
equal,  raised  on  a  stipe  above  the  first  glume,  emarginate  or  slightly 
lobed,  short-awned,  covered,  except  toward  the  apex,  with  long  silky 
hairs,  the  palea  of  the  sterile  lemma  well  developed ;  fertile  lemma 
shorter  than  the  spikelet,  cartilaginous,  smooth,  boat  shaped,  obtuse, 
the  margins  thin,  not  inrolled,  inclosing  the  margins  of  the  palea. 

Perennial  or  annual  grasses,  with  rather  open  panicles  of  silky 
spikelets.  Species  about  15,  in  the  Eastern  Hemisphere,  mostly  in 
Africa,  one  cultivated  in  the  United  States. 

Type  species:  Tricholaena  micrantha  Schrad. 

Tricholaena  Schrad.;  Schult,  Mant.  2:  163.  1824.  Three  species  are  de- 
scribed, but  the  second  and  third  are  included  in  the  genus  with  a  question. 
The  first  species  is  taken  as  the  type. 

Tricholaena  rosea  Nees  (fig.  147),  Natal  grass,  is  becoming  an 
important  forage  grass  in  the  sandy  lands  of  Florida,  where  it  has 
been  recently  introduced.  It  is  an  upright,  rather  slender  perennial, 
2  to  4  feet  tall,  with  beautiful  purple  panicles,  4  to  10  inches  long. 
The  color  varies  from. light  purple  or  pink  to  wine  color.  Although 
a  perennial,  it  is  usually  cultivated  as  an  annual,  as  it  will  not  survive 
temperatures  below  freezing. 

124.  CHAETOCHLOA  Scribn. 
(Setaria  Beauv.) 

Spikelets  subtended  by  one  to  several  bristles  (sterile  branchlets), 
falling  free  from  the  bristles,  awnless;  first  glume  broad,  usually 
less  than  half  the  length  of  the  spikelet,  3  to  5  nerved ;  second  glume 
and  sterile  lemma  equal,  or  the  former  shorter,  several-nerved;  fer- 
tile lemma  coriaceous  indurate,  smooth  or  rugose. 

Annual  or  perennial  grasses,  with  narrow  terminal  panicles,  these 
dense  and  spikelike  or  somewhat  loose  and  open.  Species  about  65, 
in  the  tropical  and  warm  temperate  regions  of  both  hemispheres;  18 
species  in  the  United  States. 

Type  species:  Panicum  viridc  L. 

Setaria  Beauv.,  Ess.  Agrost.  51,  pi.  13,  f.  3,  1812,  not  Acharius,  1789,  nor 
Michaux,  1803.  Fourteen  species  are  listed,  8.  viridis  being  illustrated.  Pani- 
cum viride  L.,  on  which  this  species  is  based,  is  taken  as  the  type. 

Chaetochloa  Scribn.,  U.  S.  Dept.  Agr.,  Div.  Agrost.  Bull.  4 :  38.  1897.  Scribner 
proposes  the  name  Chaetochloa  for  Setaria  Beauv.,  stating  that  the  name  Setaria 
was  first  used  by  Beauvois  (Fl.  Owar.  1809) 1  for  a  species  of  Pennisetum. 
Scribner  himself  applies  the  name  Chaetochloa  to  the  species  allied  to  Panicum 
viride.  Hence  it  seems  that  he  wished  to  substitute  Chaetochloa  for  Setaria 
as  used  by  Beauvois  in  his  Essai  (Ess.  Agrost.  51,  pi.  13,  f.  3,  1812).  The  figured 
species,  Setaria  viridis  (L.)  Beauv.,  becomes  the  type. 

The  name  Ixophorus  Schlecht.  was  applied  to  this  genus  by  Nash,2  but  that 
is  based  on  a  Mexican  species  not  congeneric  with  ours. 

1  According  to  Dr.  J.  H.  Barnhart  the  part  containing  Setaria  (PI.  Owar.  2:  80)   was 
not  published  until  1818. 

2  Britton  and  Brown,  Illustr.  Fl.  1 :  125.     1896. 

97769°— 19— Bull.  772 16 


242  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  147. — Natal  grass,  TricJiolaena  rosea.     Plant,  X   i  ;  spikelet  and  fertile  floret,  X  iO. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  243 

lU'al1  applied  the  name  Chamaeraphis  It.  Br.  to  American  species  of  Chae- 
tochloa, but  that  is  5111  Auslnilian  gomis  in  which  the  articulation  is  below  the 
spikelet-bearing  branches,  as  in  Peimisetum. 

One  group  of  this  genus,  section  Ptychophyllum,  has  broad,  often 
plaited,  blades  and  loose  or  open  panicles,  the  bristles  solitary  and 
at  the  base  of  only  the  uppermost  spikelets  on  the  short  branchlets. 
This  section  has  usually  been  referred  to  Panicum,  but  shows  a  closer 
relationship  to  Chaetochloa.  Two  species  of  this  group,  both  per- 
ennials, are  cultivated  in  greenhouses  or  in  the  open  in  the  Tropics 
for  ornament,  chiefly  on  account  of  the  broad  plaited  blades  that 
resemble  those  of  young  palms.  C Jiaetochloa  sulcata  (Aubl.)  Hitchc. 
(Panic  win  sulcatuui  Aubl.)  has  narrow,  rather  dense  panicles,  1  to  2 
feet  long,  and  blades  about  2  inches  wide.  Chaetochloa  palmifolium 
(Willd.)  Hitchc.  and  Chase  has  large  open  panicles  and  broader 
blades.  This  has  been  known  in  cultivation  as  Panicwm  plicatum^ 
but  is  not  P.  plicatwm,  Lam.  It  is  sometimes  called  palm-grass. 

Of  the  species  of  Chaetochloa  proper2  (Setaria  Beauv.)  several 
are  weeds  in  cultivated  soil.  Two  annual  species  are  common  in  the 
eastern  United  States,  where  they  are  known  as  foxtail  or  pigeon 
grass.  Chaetochloa  mridis  (L.)  Scribn.,  green  foxtail,  has  a  green, 
somewhat  pointed  head,  with  untwisted  blades.  Chaetochloa  lutes- 
cens  (Weigel)  Stuntz  (Setaria  glauca  of  most  authors,  not  Panicum 
glaucuni  L.)  (fig.  148),  yellow  foxtail,  has  cylindric  yellow  obtuse 
heads  and  blades  twisted  in  a  half  spiral  so  that  toward  the  end  the 
upper  surface  is  beneath. 

Another  annual  species  common  in  waste  ^places  is  Chaetochloa 
verticillata  (L.)  Scribn.,  in  which  the  bristles  are  backwardly  rough- 
ened, the  heads  thus  sticking  readily  to  clothing.  Chaetochloa  geni- 
culata  (Lam.)  Millsp.  and  Chase  is  a  perennial  species  resembling 
yellow  foxtail.  This  is  common  in  the  Southern  States  and  through- 
out the  Tropics.  Chaetochloa  magna  (Griseb.)  Scribn.,  a  robust 
annual  as  much  as  9  feet  high,  with  a  dense  panicle  or  head  as  much 
as  a  foot  long  and  2  inches  in  diameter,  is  found  in  marshes  from 
Maryland  to  the  West  Indies. 

Chaetochloa  macrostachya  (H.  B.  K.)  Scribn.  and  Merr.  (here- 
tofore commonly  confused  with  the  South  American  C.  composita 
(H.  B.  K.)  Scribn.),  is  of  some  importance  as  a  range  grass  from 
Texas  to  Arizona.  It  is  a  pale  perennial,  with  somewhat  pointed 
spikelike  panicles.  The  two  annuals,  C.  viridis  and  C.  lutescens,  are 
often  sufficiently  abundant  to  furnish  considerable  forage. 

The  most  important  species  of  the  genus  is  Chaetochloa  italica  (L.) 
Scribn.  (Setaria  italica  Beauv.).  This  is  called  millet,  or,  to  dis- 
tinguish it  from  other  kinds  of  millet,  foxtail  millet.  Millet  is  an 

1  Grasses  N.  Amer.  2:  150.     1896. 

2  The  genus  was  revised  by  Scribner  and  Merrill,  U.  S.  Dept.  Agr.,  Div.  Agrost.  Bull. 
21.     1900. 


244  BULLETIN   772,   U.   S.    DEPARTMENT   OF   AGRICULTURE. 

erect  annual,  2  to  4  feet  tall,  with  a  dense,  bristly,  yel- 
low or  purple  head.    There  are  many  varieties  in  culti- 
vation, differing  in  the  size  and  lobing  of  the  head,  the 
length  and  color  of  the  bristles,  and  the  color  of  the 
seed.    Small  forms  resemble  C.  viridis,  but  may  be  dis- 
tinguished by  the  articulation  of  the  seed.    In  C.  viridis 
the  seed  (fruit,  that  is,  the  fertile  floret)  falls  from  the 
pedicel  inclosed  within  the  glumes.     In  C.  italica  the 
seed  readily  separates  from  the 
glumes  b}T  an  articulation  above 
the  sterile  lemma.     A  ripe  head 
of  C.  italica  rubbed  between  the 
palms  yields  free  seed.     A  head 
of    C.    viridis   will    yield    entire 
spikelets. 


FIG.   148. — Yellow  foxtail,    Chaetochloa   lutesccns.     Plant,    X    I;   two   views  of  spikelet 

and  fertile  floret,  X  10. 

The  varieties  of  Chaetochloa  italica  cultivated  in  the  United  States 
have  been  classified  as  follows1  (under  Setaria  italica)  : 

Fruit  dark  colored   (reddish  or  orange  to  blackish  or  brownish  black). 

Fruit  reddish  or  orange rubrofructa. 

Fruit  blackish,  brownish  black,  or  purplish  black  with  pale  yellowish 

straw  lines  intermingled,  these  sometimes  predomina.ting_?u'firro/Twcto. 


1  See  Hubbard,  Amer.  Journ.  Bot  2 :  187.     1915. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  245 

Fruit  pale  (yellowish  to  straw  or  light  brown). 
Bristles  green. 

Panicle  more  or  less  open-lobulate stramineofructa. 

Panicle  dense  or  slightly  lobulate  at  base germanica. 

Bristles  brown  or  purple. 

Bristles  brown brunneoseta. 

Bristles  purple. 

Panicle  more  or  less  lobulate hostii. 

Panicle  dense  or  slightly  lobulate  at  base metzgeri. 

Subsp.  ntbrnfructa  Hubb. :  The  only  forms  cultivated  in  the  United  States 
are  var.  pitrpiircoscta  Ilubb.,  Turkish  millet,  with  purple  bristles  and  a  large 
lobulate  head;  and  subvar.  violacea  (Alef.)  Hubb.,  Kursk  millet  or  Siberian 
millet,  with  purple  bristles  and  a  smaller  dense  head. 

Subsp.  niyrofructa  Hubb. :  The  common  form  cultivated  in  the  United  States 
is  var.  atra,  or  Hungarian  grass.  This  has  small  dense  heads  1  to  3  inches  long 
with  purple  bristles. 

Subsp.  stramineofructa  Hubb.,  German  millet:  Plants  robust  with  heads  4 
to  12  inches  long  and  as  much  as  2  inches  wide,  the  bristles  noticeably  longer 
than  tbo  spikolots.  Forma  breviseta  (Doell)  Hubb.,  Golden  Wonder  millet, 
differs  in  having  bristles  shorter  than  the  spikelets  or  barely  exceeding  them. 

Subsp.  germanica  (Mill.)  Hubb.,  common  millet:  Heads  mostly  2  to  3  inches 
long,  one-fourth  to  one-half  an  inch  thick,  the  bristles  noticeably  longer  than 
the  spikelets;  forma  mitis  (Alef.)  Hubb.  with  bristles  shorter  than  the  spike- 
lets  or  barely  exceeding  them.  There  has  been  an  unfortunate  misapplication 
of  the  name  German  millet.  The  forms  cultivated  under  this  name  are  not 
the  subspecies  germanica  as  one  would  suppose  (see  the  preceding  subspecies). 
Var.  bfunneoseta  Hubb.,  Aino  millet :  Head  large,  lobulate,  brown.  Subvar. 
densior  Hubb.  has  a  compact  scarcely  lobulate  head. 

Var.  hostii  Hubb.,  German  millet :  Head  large,  lobulate,  purple ;  differs  from 
the  other  form  of  German  millet  (subsp.  stramineofructa)  in  having  purple 
bristles. 

Var.  metzgeri  (Kornicke)  Hubb.,  common  millet:  Bristles  noticeably  longer 
than  the  spikelets;  differs  from  the  other  form  of  common  millet  (subsp.  ger- 
manica'] in  having  purple  bristles;  sometimes  called  Hungarian  grass,  a  name 
which  should  be  applied  to  subsp.  nigrofructa. 

125.  PENNISETUM  Rich. 

Spikelets  solitary  or  in  groups  of  two  or  three,  surrounded  by  an 
involucre  of  bristles,  these  not  united  except  at  the  very  base,  often 
plumose,  falling  attached  to  the  spikelets;  first  glume  shorter  than 
the  spikelet,  sometimes  minute  or  wanting;  second  glume  shorter 
than  or  equaling  the  sterile  lemma;  fertile  lemma  chartaceous, 
smooth,  the  margin  thin,  inclosing  the  palea. 

Annual  or  perennial,  often  branched  grasses,  with  usually  flat 
blades  and  dense  spikelike  panicles.  Species  about  50,  in  the  tropical 
regions  of  both  hemispheres ;  1  species  in  southern  Florida. 

Type  species:  Pennisetnm  typhoideum  Rich. 

Penniseturn  Rich.,  in  Pers.  Syn.  PI.  1 :  72.  1805.  Five  species  are  described, 
1\  typhoideum,  P.  setosum,  P.  cenehroides,  P.  orientale,  and  P.  molaceum. 
Pennisetum  typhoideum,  being  a  well-known  economic  species,  is  chosen  as  the 
type. 


246  BULLETIN   772,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 


Penicillaria  Willd.,  Enum.  PL  2:  1036.  1809.  A  single  species,  p.  spicatus, 
based  on  Holcus  sjncatus  L.,  is  described. 

Gymnothrix  Beauv.,  Ess.  Agrost.  59,  pi.  13.  f.  6.  1812.  The  type  species  is 
G.  thourii,  the  one  figured.  Beauvois  distinguished  Gymnothrix  from  Pen- 
niseturn  by  the  glabrous  (not  plumose)  bristles. 

The  most  important  species  of  the  genus  is  Pennisetum 
glaucum  (L.)  R.  Br.  (P.  typkoideumRich.,  P.  ameri- 
canum  (L.)  Schum.,  Penicillaria  spicata  (L.)  Willd.), 
called  in  this  country  pearl  millet  (fig.  149).  This  is  a 
robust  annual,  4  to  8  feet  tall,  with  broad  blades  like 
those  of  corn  or  sorghum,  and  a  dense,  erect,  cylindric 
spikelike  panicle  as  much  as  a  foot  long,  the  stem  woolly 
below  the  spike,  the  involucre  containing  usually  two 
spikelets  about  as  long  as  the  bristles.  Pearl  millet  dif- 
fers from  the  other  Paniceae  in  having  an  enlarged  cary- 
opsis  bursting  through  its  lemma  and  palea.  The  cary- 
opsis,  or  "seed,"  is  deciduous  by  an  articulation  above 
the  fertile  lemma,  the  bristles  and  the  floral  bracts  re- 
maining on  the  spike.  Pearl  millet  is  widely  cultivated 
in  tropical  Africa  and  Asia,  the  seed  being  used  for  hu- 
man food.  The  species  has  been  cultivated  since  pre- 


FIG.  149. — Pearl  millet,  Pennisetum  glaucum.     Inflorescence,   X    \  ',  two  views  of  spikelet 

and  caryopsis,   X   10. 

historic  times,  its  wild  prototype  being  unknown.  In  the  United 
States  pearl  millet  is  used  to  a  limited  extent  in  the  Southern  States 
for  forage,  especially  for  soiling. 


GENERA  OF   GRASSES   OF  THE   UNITED  STATES.  247 

Panicum  glaucum  L.  (Sp.  PI.  56.  1753),  on  which  was  based  Pen- 
nisetum glaucum,  was  itself  based  on  a  citation  from  the  Flora  Zey- 
lanica  (Panicum  spica  te^eti,  involucris  bifloris  fasciculato-pilosis  L. 
Fl.  Zeyl.  18.  1747),  which  refers  to  the  species  afterwards  described 
as  Pennisetum  typhoideum.  Linnaeus  described  two  varieties  of 
Panicum  glauwm,  these  being  now  called  Chaetochloa  viridis  and  C. 
lutescens.  Through  an  error  the  name  Panicum  glaucum  has  been 
applied  by  nearly  all  botanists  to  the  latter  species.  When  the 
species  was  transferred  to  Setaria  and  to  Chaetochloa  the  error  was 
perpetuated.  Robert  Brown  transferred  Panicum  glaucum  to  Pen- 
nisetum but  used  the  name  in  the  erroneous  sense,  as  is  shown  by  his 
description.  Nevertheless,  Robert  Brown  must  be  credited  with  the 
name  Pennisetum  glaucum  even  though  he  described  the  wrong 
species.  The  only  species  of  Pennisetum  found  native  in  the  United 
States  is  P.  setosum  (Swartz)  Rich.  (fig.  150),  of  tropical  America, 
which  extends  into  southern  Florida.  Two  species  are  cultivated 
for  ornament.  *  Pennisetum  villosum  R.  Br.  (P.  longistylum  of  flor- 
ists, not  Hochst.)  is  a  slender  perennial  1  or  2  feet  tall  with  a  pale 
feathery  head  2  to  4  inches  long,  the  bristles  1  to  2  inches  long. 
Pennisetum  ruppelii  Steud.,  fountain  grass,  with  beautiful  pink  or 
purple  nodding  spikes,  longer  and  more  graceful  than  those  of  the 
preceding,  is  used  for  borders.  An  African  species,  Napier  grass 
(P.  purpureum  Schum.),  has  been  tested  recently  in  the  Southern 
States  as  a  forage  plant.  It  is  a  coarse  perennial  8  to  12  feet  tall. 

126.  CENCHETJS  L. 

Spikelets  solitary  or  few  together,  surrounded  and  inclosed  by  a 
spiny  bur  composed  of  numerous  coalescing  bristles  (sterile  branch- 
lets),  the  bur  globular,  the  peduncle  short  and  thick,  articulate  at 
base,  falling  with  the  spikelets  and  permanently  inclosing  them,  the 
seed  germinating  within  the  old  involucre,  the  spines  usually 
retrorsely  barbed. 

Annual  or  sometimes  perennial,  commonly  low  branching  grasses, 
with  flat  blades  and  racemes  of  burs,  the  burs  readily  deciduous. 
Species  about  25,  in  the  warmer  parts  of  both  hemispheres,  but  chiefly 
in  America;  7  species  in  the  United  States,  chiefly  in  the  south- 
ern portion. 

Type  species:  Cenchrus  echinatus  L. 

Cenchrus  L.,  Sp.  PI.  1049,  1753 ;  Gen.  PI.,  ed.  5,  471.  1754.  Linnaeus  describes 
five  species,  C.  racemosus,  C.  capitatus,  C.  echinatus,  C.  tribuloides,  and  C.  fru- 
tescens.  The  reference  in  the  Genera  Plantarum  is  to  Panicastrella  Mich.  31,  that 
is,  to  plate  31  of  Micheli's  Nova  Plantarum  Genera,  published  in  1729.  The  ac- 
count of  the  genus  Panicastrella  is  on  page  36.  The  two  species  here  described 
are  cited  as  synonyms  by  Linnaeus,  under  Cenchrus  echinatus  and  C.  tribuloides, 
both  being  based  on  descriptions  in  Sloane's  History  of  Jamaica.  The  first 
species,  C.  echinatus,  is  chosen  as  the  type.  Cenchrus  racemosus  is  now  referred 
to  Nazia ;  C.  capitatus  to  Echinaria.  Cenchrus  frutescens,  of  which  there  is  no 
specimen  in  the  Linnaean  Herbarium,  is  uncertain.  It  is  stated  to  come  from 
America,  but  this  is  a  misprint  for  Armenia,  as  is  shown  by  the  second  edition  of 
the  Species  Plantarum, 


248  BULLETIN    772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 


FIG.   150. — Pennisetum  setosum.     Plant,    X    1  ;  two  views  of  spikelet  and   fertile   floret, 

X   10. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  249 

Rarum  Adans.,  Fain.  PI.  2:  35,  597.  1763.  Of  the  four  pre-Linnsean  citations 
two  are  given  by  Linntmis  under  Ccnclirux  echinatus,  which  is  taken  as  the  type. 

Cenchropsis  Nash,  in  Small,  Fl.  Southeast.  U.  S.  109.  1903.  Cenchrus  myosu- 
roides  H.  B.  K.  is  designated  as  the  type. 

Nastus  Lunell,  Amer.  Midi.  Nat.  4:  214.  1915.  The  name  is  ascribed  to 
Dioscorides  and  "  Cenchrus  frutescens  Linn."  given  as  the  type.  Lunell  intends 
in  apply  the  name  to  Cenchrus,  but  the  designated  type  is  unidentifiable  and 
certainly  is  not  a  grass. 

Most  of  the  species  of  the  United  States  are  annual.  Cenchrus 
myosuroides  H.  B.  K.  differs  from  our  other  species  in  the  involucre, 
or  bur,  with  bristles  united  only  at  the  base.  Were  it  not  for  certain 
species  of  Australasia  which  are  intermediate,  this  species  might  be 
segregated  under  a  distinct  genus,  as  was  done  by  Nash.1  The  original 
C.  tribuloides  L.  (fig.  151)  is  a  dune  grass  of  the  Atlantic  coast,  with 
large  villous  burs.  The  common  sand  bur  of  the  interior  found  in 
sandy  fields  across  the  continent  is  C.  pauciflorus  Benth.  This  was 
formerly  confused  with  C.  tribuloides  and  more  recently  has  been 
called  C.  carolinianus  Walt.,  which  proves  to  be  a  different  species. 
Cenchrus  echinatus,  a  common  tropical  species  extending  into  the 
Southern  States,  has  a  less  prickly  bur,  with  a  ring  of  slender  bristles 
at  the  base  of  the  stout  prickles.  The  species  of  Cenchrus,  especially 
the  last  two,  are  excellent  forage  grasses  before  the  burs  are  formed. 
The  genus  has  been  revised  by  Nash.2 

127.  AMPHICARPON  Raf. 

Spikelets  of  two  kinds  on  the  same  plant,  one  in  a  terminal  panicle, 
perfect  but  not  fruitful,  the  other  cleistogamous  on  slender  leafless 
subterranean  branches  from  the  base  of  the  culm  or  sometimes  also 
from  the  lower  nodes;  first  glume  of  the  aerial  spikelets  variable 
in  size,  sometimes  obsolete;  second  glume  and  sterile  lemma  about 
equal;  lemma  and  palea  indurate,  the  margins  of  the  lemma  thin 
and  flat;  fruiting  spikelets  much  larger,  the  first  glume  wanting; 
second  glume  and  sterile  lemma  strongly  nerved,  subrigid,  exceeded 
at  maturity  by  the  turgid,  elliptic,  acuminate  fruit  with  strongly 
indurate  lemma  and  palea,  the  margins  of  the  lemma  thin  and  flat; 
stamens  with  small  anthers  on  short  filaments. 

Annual  or  perennial  erect  grasses,  with  flat  blades  and  narrow 
terminal  panicles.  Species  two,  in  the  Atlantic  Coastal  Plain  region 
of  the  United  States. 

Type  species:  Milium  ampMcarpum  Pursh. 

Amphicarpon  Raf.,  Amer.  Month.  Mag.  2 :  175.  1818.  In  a  review  of  Pursh's- 
Flora  of  North  America,  Rafmesque  indicates  that  Milium  amphicarpon  should 
be  a  new  genus,  Amphicarpon  Raf.  Kunth  8  published  the  genus  Amphicarpum, 
based  on  the  same  type,  apparently  ignorant  of  Rafinesque's  proposed  name. 

1  Censhropsis  myosuroldcs  (H.  B.  K.)  Nash,  in  Small,  Fl.  Southeast,  U.  S.  109.     1903. 

2  Bull.  Torrey  Club  22:  298-301.     1895. 

3  Rev.  Gram.  1:  28.     1829. 


250  BULLETIN   772,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 

The  two  species  are  AmpMcarpon  purshii  Kunth  (A.  amphicarpon 
(Pursh)   Nash),  an  annual   (fig.  152),  with  hirsute  blades,  found 


FIG.  151. — Cenchrus  tribuloides.     Plant,    X    \  ;  two  views  of  spikelet  and  fertile  floret, 

X  10. 

from  New  Jersey  to  Florida,  and  A.  florid anum  Chapm.,  a  stolonif- 
erous  perennial,  with  glabrous  blades,  confined  to  Florida.  The 
latter  often  provides  abundant  pasture. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


251 


FIG.   152. — Amphicarpon  purshu.     Plant,    X    I  ;  two  views  of  aerial  spikelet  and  floret 
and  the  subterranean  spikelet  and  fertile  floret,   X   10. 


252  BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 

Olyra  L.,  Syst.  Nat.,  ed.  10,  2: 1261.  1T59.  A  tropical  American 
genus,  one  species  of  which,  0.  latifolia-  L.  (fig.  153)  is  credited 
to  Florida  by  Small  in  his  Flora  of  the  Southeastern  United  States. 
The  record  is  doubtful. 

A  glabrous  perennial,  bamboolike  in  aspect,  as  much  as  15  feet 
tall,  the  branches  straggling  over  shrubs;  blades  petiolate,  asym- 
metrically lanceolate-oblong,  as  much  as  8  inches  long  and  2  inches 
wide;  panicles  4  to  6  inches  long,  the  branches  stiffly  ascending  or 
spreading,  each  bearing  a  single,  large,  long-acuminate,  pistillate 
spikelet  at  the  thickened  summit  and  several  small  slender-pediceled 
staminate  spikelets  along  the  branch. 

13.  ANDROPOGONEAE,   THE  SORGHUM  TRIBE. 

128.  IMPERATA  Cyrillo. 

Spikelets  all  alike,  awnless,  in  pairs,  unequally  pedicellate  on  a 
slender  continuous  rachis,  surrounded  by  long  silky  hairs;  glumes 
about  equal,  membranaceous ;  sterile  lemma,  fertile  lemma,  and  palea 
thin  and  hyaline. 

Perennial,  slender,  erect  grasses,  with  terminal  narrow  woolly  pani- 
cles. Species  seven,  in  the  tropical  regions  of  both  hemispheres ;  two 
species  in  the  United  States,  three  others  in  tropical  America. 

Type  species :  Lagnrus  cyUndrieus  L. 

Imperata  Cyrillo,  PI.  Rar.  Neap.  2:  26.  1792.  A  single  species  is  described, 
/.  arundinacea  Cyrillo,  but  the  genus  is  based  upon  Lagurus  cylindricus  L.1 

Our  species  are  Imperata  l>rasUiensis  Trin.,  in  southern  Florida, 
and  /.  hookcri  Rupr.  (fig.  154),  from  western  Texas  to  southern 
California.  They  are  not  found  in  sufficient  abundance  to  be  of 
agricultural  value. 

129.  MISCANTHTJS  Anderss. 

Spikelets  all  alike,  in  pairs  unequally  pedicellate  along  a  slender 
continuous  rachis ;  glumes  equal,  membranaceous  or  somewhat  coria- 
ceous; sterile  lemma  a  little  shorter  than  the  glumes,  hyaline;  fertile 
lemma  hyaline,  smaller  than  the  sterile  lemma,  extending  into  a  deli- 
cate bent  and  flexuous  awn ;  palea  small  and  hyaline. 

Robust  perennials,  with,  long  flat  blades  and  terminal  panicles  of 
aggregate  spreading  slender  racemes,  our  species  with  a  tuft  of 
silky  hairs  at  the  base  of  the  spikelet,  surrounding  it  and  of  about 
the  same  length  as  the  glumes,  the  palea  of  the  short-pedicellate  spike- 
let  about  one-fourth  as  long  as  the  lemma,  the  palea  of  the  long- 
pedicellate  spikelet  obsolete.  Species  about  eight,  in  southeastern 
Asia  and  South  Africa ;  one  cultivated  in  the  United  States. 

1  Cyrillo  gives  the  generic  heading  thus  :  "  Imperata.  Lagurus  cylindricus  Linn.,  Sp. 
PI.  120,  n.  2." 


GENEEA   OF   GRASSES   OF   THE   UNITED   STATES.  253 


FIG.  153. — Olyra  latifolia.     Plant,    X    I  ;  pistillate  spikelet,  fertile  floret,  and  staminate 

spikelet,   X   5, 


254  BULLETIN   772,   U.   S.    DEPARTMENT   OF   AGRICULTURE. 

Type  species:  Mixcantlinx  jnpoiiirn*  Anderss. 

Miscanthus  Anderss.,  Ofv.  Svensk.  Vet.  Akad.  Forh.  1855:  165.  1856.  Anders- 
son  describes  five  species,  M.  capenms,  M.-japoni-cus,  J/.  luzonensis,  M.  sinensis, 
and  M.  purpurascens.  Andersson  states  that  M.  capensis  is  a  transition  from 


••n 


FIG.  154. — Imperata  hookeri.    Plant,  X   1  ;  spikelet,   X  5. 

this  group  to  the  other  genera  of  the  tribe ;  hence  this  species  may  be  excluded 
from  consideration  in  selecting  the  type  of  the  genus.  The  second  species,  M. 
japonicus,  is  therefore  selected  as  the  type. 


GENERA   OF   GRASSES    OF   THE    UNITED   STATES.  255 

Xiphagrostis  Coville,  Contr.  U.  S.  Nat.  Herb.  9:  399,  pi.  69.  1905.  Two 
spec'ies  are  included,  X.  floridula  (Labill.)  Coville  and  X.  japonica  (Thunb.) 
Coville.  Saccharum  floridulum  Labill.,  on  which  the  first  species  is  based,  is 
designated  as  the  type.  Coville  assumed  M.  capensis  to  be  the  type  of  Miscan- 
thus,  as  it  was  the  first  species  described  (see  Miscanthus,  p.  254),  and  referred 
Mi  Acanthus  sinensis  and  its  allies,  which  were  not  congeneric  with  M.  capensis, 
to  Xiphagrostis. 

Miscanthus  sinensis  Anderss.  (PI.  XVIII;  fig.  155)  is  cultivated  in 
the  United  States  as  an  ornamental.  Commercially  it  is  known  as 
Eulalia  japonica  or  merely  eulalia.  This  is  a  reedy  grass  4  to  8  feet 
high,  growing  in  large  bunches,  with  flat  mostly  basal  blades,  2  to  3 
feet  long  and  about  half  an  inch  wide,  gradually  narrowed  to  a 
slender  point,  the  panicle  somewhat  fan  shaped,  consisting  of  nu- 
merous silky  racemes  4  to  8  inches  long,  aggregate  at  the  summit  of 
the  culm.  Eulalia  has  escaped  from  cultivation  and  is  found  grow- 
ing wild  in  some  localities.  There  are  two  varieties  of  Miscanthus 
sinensis  with  variegated  leaves,  var.  variegatus  Beal,  with  striped 
blades,  and  var.  zebrinus  Beal,  with  banded  blades.  Miscanthus 
sinensis  gracillimus  is  a  variety  with  very  narrow  blades.  Another 
species,  M.  nepalensis  (Trin.)  Hack.,  is  occasionally  cultivated  under 
the  name  of  Himalaya  fairy  grass.  This  has  spikelets  about  one- 
fourth  as  long  as  the  hairs  at  their  base. 

130.  SACCHARTJM  L. 

Spikelets  in  pairs,  one  sessile,  the  other  pedicellate,  both  perfect, 
awnless,  arranged  in  panicled  racemes,  the  axis  disarticulating  below 
the  spikelets;  glumes  somewhat  indurate,  sterile  lemma  similar  but 
hyaline ;  fertile  lemma  hyaline,  sometimes  wanting. 

Perennial  grasses  of  tropical  regions,  including  about  10  species. 

Type  species :  Saccharum  offldnarum  L. 

Saccharum  L.,  Sp.  PI.  54,  1753 ;  Gen.  PL,  ed.  5,  28.  1754.  Two  species  are  de- 
scribed. The  first  is  chosen  as  the  type,  because  it  is  a  well-known  economic 
species.  The  second  species,  S.  spicatum,  is  now  referred  to  the  genus  Imperata. 

Saccharum  officmarwn  (fig.  156),  the  sugar  cane,  is  cultivated  in 
Louisiana  and  to  a  limited  degree  in  some  of  the  other  Gulf  States. 
It  is  a  tall  stout  grass,  8  to  15  feet  tall  or  even  taller,  with  solid  juicy 
stems,  broad  flat  blades,  and  large  plumelike  panicles  1  to  2  feet 
long,  with  numerous  small  spikelets  about  3  mm.  long,  each  sur- 
rounded at  the  base  by  a  tuft  of  silky  hairs  two  or  three  times  as 
long  as  the  spikelet.  The  glumes  and  the  delicate  sterile  lemma  are 
about  the  same  length,  the  fertile  lemma  and  palea  being  absent. 
Sugar  cane  is  cultivated  chiefly  for  the  production  of  sugar  and 
molasses;  but,  especially  in  the  Gulf  States  outside  of  Louisiana,  it  is 
also  used  for  forage. 

131.  ERIANTHUS  Michx. 

Spikelets  all  alike,  in  pairs  along  a  slender  axis,  one  sessile,  the  other 
pedicellate,  the  rachis  disarticulating  below  the  spikelets,  the  rachis 


256          BULLETIN   772,   U.   S.   DEPARTMENT   OF   AGRICULTURE. 


FIG.  155. — Eulalia,    MiscantHus  sinensis.     Sketch  of  several  stems,  much  reduced  ;  branch 
of  panicle,  X   |  ;  spikelet,  X  5, 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES. 


257 


FIG.   156. — Sugar  cane,  Saccharum  offlcinarum.     Sketch  of  three  stems,  much  reduced; 
a  few  branches  of  panicle,   X   \  ',  spikelet  with  pedicel  of  second  spikelet   (the  shorter) 
.    and  joint  of  rachis,   X   5. 

97769°— 19— Bull.  772 17 


258  BULLETIN   772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 

joint  and  pedicel  falling  attached  to  the  sessile  spikelet;  glumes 
coriaceous,  equal,  usually -copiously  clothed,  at  least  at  the  base,  with 
long  silky  spreading  hairs;  sterile  lemma  thin  and  hyaline;  fertile 
lemma  hyaline,  the  midnerve  extending  into  a  slender  awn;  palea 
small  and  hyaline. 

Perennial  reedlike  grasses,  with  flat  blades  and  terminal  oblong, 
usually  dense  silky  panicles.  Species  about  20,  in  the  warmer  regions 
of  both  hemispheres ;  five  in  the  United  States,  mostly  in  the  Atlantic 
Coastal  Plain. 

Type  species :  Erianthus  saccJiaroides  Michx. 

Erianthus  Michx.,  Fl.  Bor.  Amer.  1 :  54.  1803.  Michaux  describes  two  species, 
E.  saccJiaroides  and  E.  brevibarbis.  He  derives  the  name  of  the  genus  from 
two  Greek  words  which  mean  hairy  flower,  because  of  the  very  densely  villous 
involucre  below  the  spikelets,  and  he  remarks  that  the  genus  is  closely  allied 
to  Saccharum.  The  first  species,  with  long  involucral  hairs,  he  names 
sacchar  aides,  and  the  second,  with  short  hairs,  brevibarbis.  The  first  species, 
better  representing  Michaux's  idea  of  the  genus,  is  chosen  as  the  type. 

The  commonest  native  species  is  Erianthus  saccJiaroides  (fig.  157) , 
with  straight  awns  and  woolly  panicles.  Erianthus  divaricatus  (L.) 
Hitchc.,  with  pale  panicles,  and  E.  contortus  Baldw.,  with  dark 
panicles,  have  flat,  .twisted  awns.  Erianthm  strictus  Baldw.  has 
naked  spikelets,  and  E.  'brevibarbis  Michx.  has  short  hairs  at  the  base 
of  the  spikelets.  The  plants  are  too  coarse  to  be  of  value  for  grazing, 
but  some  of  our  native  species  might  well  be  cultivated  for  ornament. 

One  species,  E.  ravennae  (L.)  Beauv.,  a  native  of  the  Mediterranean 
region,  is  occasionally  cultivated  for  ornament  because  of  the  silky 
plumes.  It  is  called  Ravenna  grass  and  also  by  the  less  distinctive 
names,  plume-grass  and  hardy  pampas  grass.  The  culms  are  several 
feet  high,  growing  in  large  clumps,  with  blades  about  half  an  inch 
wide,  tapering  into  a  long  slender  point,  the  plume  being  as  much  as 
2  feet  long. 

132.  ANDROPOGON  L. 

Spikelets  in  pairs  at  each  node  of  an  articulate  rachis,  one  sessile 
and  perfect,  the  other  pedicellate  and  either  staminate,  neuter,  or  re- 
duced to  the  pedicel,  the  rachis  and  the  pedicels  of  the  sterile  spikelets 
often  villous,  sometimes  conspicuously  so ;  glumes  of  the  fertile  spike- 
let  coriaceous,  narrow,  awnless,  the  first  rounded,  flat,  or  concave  on 
the  back,  several-nerved,  the  median  nerve  weak  or  wanting;  sterile 
lemma  shorter  than  the  glumes,  empty,  hyaline;  fertile  lemma 
hyaline,  narrow,  entire  or  bifid,  usually  bearing  a  bent  and  twisted 
awn  from  the  apex  or  from  between  the  lobes;  palea  hyaline,  small 
or  wanting;  pedicellate  spikelet  awnless,  sometimes  staminate  and 
about  as  large  as  the  sessile  spikelet,  sometimes  consisting  of  one  or 
more  reduced  glumes,  sometimes  wanting,  only  the  pedicel  present. 

Rather  coarse  perennials  (in  the  United  States),  with  solid  culms, 
the  spikelets  arranged  in  racemes,  these  numerous,  aggregate  on  an 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  259 


FIG.  157.— Plume-grass,  Erianthus  saccharoides.     Plant,    X    \.  ;  spikelet  with  pedicel   (at 
right)  and  joint  of  rachis,   X   5. 


260  BULLETIN   772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 

exserted  peduncle,  or  single,  in  pairs,  or  sometimes  in  threes  or  fours, 
the  common  peduncle  usually  inclosed  by  a  spathelike  sheath,  these 
sheaths  often  numerous,  forming  a  compound  inflorescence,  usually 
narrow,  but  sometimes  in  dense  subcorymbose  masses.  Species  about 
150,  in  all  warmer  parts  of  the  world ;  about  30  species  in  the  United 
States,  mostly  in  the  South. 

Type  species    Andropogon    -rirginicus  L. 

Andropogon  L.,  Sp.  PI  1045,  1753 ;  Gen.  P1M  ed.  5,  468.  1754.  Linnreus  de- 
scribes 12  species.  The  reference  in  the  Genera  Plantarum  is  to  "  Roy.  Ingdb. 
52."  In  this  work,  Flora  Leydensis,  published  in  1740,  Royen  describes  two 
species,  the  first  of  these  is  later  (Species  Plantarum)  named  Andropogon  lilrtum 
by  Linnaeus,  and  the  second  A.  virgin  icu  in.  The  type  should  be  chosen  from  these 
two.  The  two  species  appear  to  be  equally  familiar  to  Royen  and  to  Linnaeus, 
though  A.  rirginicus  is  more  fully  described  and  has  priority  of  position  in 
the  Species  Plantarum.  Andropogon  rir<iinicns  is  chosen  as  the  type,  as  this 
choice  retains  the  generic  name  for  its  usual  signification.  Of  the  12  species 
originally  described,  4  are  retained  in  Andropogon,  A.  d-istaclu/os,  A.  vir- 
ginicus,  A.  bicornis,  and  A.  ischaemum.  Andropogon  contortus  is  now  referred  to 
Heteropogon,  A.  divaricatus  to  Erianthus,  A.  nutans  to  Sorghastrum,  A.  alope- 
curoides  to  Erianthus,  A.  scfioenantlms,  A.  liirtus,  and  A.  nardus  to  Cymbopo- 
gon.  Andropogon  fasciculatus,  the  last  species,  is  unidentifiable. 

Schizachyrium  Nees,  Agrost.  Bras.  331.  1829.  The  type  species  is  Andro- 
pogon condensatus  H.  B.  K.,  upon  which  is  based  8.  condensatnm,  first  of  the  six 
species  described.  Nees  states,  in  a  paragraph  at  the  end  of  the  generic  descrip- 
tion, that  besides  the  species  he  enumerates  Andropogon  brevifolms  belongs  to 
Schizachyrium.  Because  of  this  statement  Nash1  chooses  the  latter  species 
as  the  type.  This  group  includes  the  species  of  Andropogon  with  racemes 
single  at  the  ends  of  the  branches. 

Dimeiostemon  Raf.,  Bull.  Bot.  Seringe  1 :  221.  1830.  "Andropogon  vaginatus 
Ell.,  A.  sessiliflorus  [nomen  nudurn],  A.  macrurus,  A.  vaginatus  [repeated],  A. 
tetrastachys"  are  listed.  Andropogon  vaginatus  Ell.,  which  is  the  same  as 
A.  virginicus  L.,  is  taken  as  the  type. 

Amphilophis  Nash,  in  Britton,  Man.  71.  1901.  Only  one  species  described,  An- 
dropogon torreyanus  Steud.  This  group  includes  the  species  of  Andropogon 
with  numerous  racemes  in  a  naked  panicle.  Amphilophis  was  first  used  by 
Trinius 2  as  a  section  of  Andropogon. 

Our  species  are  divided  into  three  groups:  One  (constituting  the 
genus  Schizachyrium  of  some  authors)  Avith  the  racemes  single  on 
each  peduncle ;  two,  with  the  racemes  in  pairs,  or  sometimes  in  threes 
or  fours,  on  each  peduncle ;  three,  with  the  racemes  aggregate  toward 
the  naked  summit  of  the  culms  and  branches.  The  commonest  repre- 
sentative in  the  United  States  of  the  first  group  is  Andropogon  scopa- 
rius  Michx.  (fig.  158).  This  is  an  erect  bunch-grass  2  to  4  feet  high, 
the  racemes  scattered  along  the  upper  part  of  the  stem.  It  is  common 
throughout  the  eastern  half  of  the  United  States.  It  is  a  fairly  good 
forage  grass  and  forms  a  part  of  the  wild  prairie  hay  in  the  eastern 
portion  of  the  Great  Plains,  where  it  is  called  little  bluestem.  The  sec- 
ond group  is  represented  by  numerous  species  in  the  Southern  States. 
One  of  these,  A.  virginicus  L.  (fig.  159)  is  found  in  old  fields,  open 
woods,  and  sterile  ground  from  Massachusetts  to  Texas  and  Florida. 
This  is  called  broom  sedge,  though  the  name  is  also  applied  to  some 
of  the  other  species  of  Andropogon.  Andropogon  virginicus  is  a 

iN.  Amer.  Fl.  17:   100.      1912. 

2M«5m.  Acad.  St.   Petersb.  VI.  2:   285.     1832. 


GENERA   OF   GRASSES   OF   THE  "UNITED   STATES. 


261 


bunch-grass  with  tall  slender  culms,  the  feathery  racemes- in  pairs, 
the  rachis  flexuous,  the  short  common*  peduncle  and  usually  the  lower 
part  of  the  racemes  inclosed  in  the  inflated  sheathing  bract, 


FIG.  158. — Little  biucstem,  Andropogon  scopa- 
rius.  riant,  X  I  ;  pair  of  spikelets  with 
joint  of  rachis  (at  left),  X  5. 


these  bracts  scattered 
along  the  culm  on  short 
branches.  An  allied  spe- 
cies, A.  elliottii  Chapm., 
found  in  the  Southeast- 
ern States,  is  distin- 
guished by  the  conspicu- 
ously inflated  upper 
foliage  sheaths,  the  blade 
being  often  reduced  to  an 
appendage.  Another  im- 
portant species,  belong- 
ing to  this  group  but  dif- 
fering in  aspect  from  the 


262          BULLETIN   772,   U.   S;   DEPARTMENT   OF   AGRICULTURE. 


FIG.  159. — Broom  sedge,  Andropogon  virgin  icits.  Plant  X  I  ;  pair  of  spikelets  with 
joint  of  rachis  (at  left),  the  second  spikelet  obsolete,  the  hairy  pedicel  only  present, 
X  5. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  263 

last,  is  A.  fut-catus  Muhl.  (PL  XIX;  fig.  1GO).  This  grows  through- 
out the  eastern  half  of  the  United  States  and  is  an  important  forage 
grass  in  the  western  portion  of  its  range.  Here  it  is  the  chief  con- 
stituent of  prairie  hay  and  is  known  as  big  bluestem.  It  is  a 
tall,  usually  purplish  bunch-grass,  the  racemes  only  slightly  hairy, 
borne  in  twos  to  fours  at  the  ends  of  the  culms  and  the  short 
branches,  the  rachis  strict.  In  the  Great  Plains,  grasses  are  popu- 
larly divided  into  tall  grasses  and  short  grasses.  The  former,  of 
which  A.  furcatus  is  the  most  important,  are  found  chiefly  in  the 
valleys  and  draws;  the  latter,  including  buffalo  grass  and  grama 
grass,  are  found  on  the  uplands.  The  third  group  of  Andropogon 
is  represented  in  this  country  by  only  three  species,  all  extending 
northward  from  Mexico  into  the  Southwestern  States.  The  very 
hairy  or  feathery  racemes  are  crowded  in  an  oblong  or  somewhat 
flabellate  white  panicle  terminating  the  main  culm  and  its  branches. 
One  of  these,  J..  saccharoides  Swartz  (fig.  161)  (A.  argenteus  DC., 
-L-1.  "barblnodis  Lag.),  is  distinguished  by  the  bearded  nodes.  Andro- 
pogon saccharoides  laguroides  (DC.)  Hack.  (A.  torreyanus  Steud.), 
with  more  slender  culms  and  smooth  nodes,  is  found  as  far  north  as 
Kansas.  Another  species  of  the  group,  A.  perforatus  Trin.,  of 
Moxioo,  rare  in  this  country,  differs  in  having  a  little  pinhole  or.  pit 
in  the  first  glume. 

An  allied  group  of  grasses  is  of  importance  in  tropical  parts  of 
the  Old  World  because  of  the  essential  oils  obtained  from  them. 
They  are  included  in  Andropogon  by  some  authors,  but  are  referred 
by  others  to  Cymbopogon.  A  full  account  of  these  grasses  is  given 
by  Stapf.1  The  most  important  are  citronella  grass  (Andropogon 
nardus  L. ;  Cymbopogon  nardus  Rendle)  and  lemon  grass  (Andro- 
pogon citratus  DC.,  Cymbopogon  citratus  Stapf).  These  are  robust 
grasses  with  large  compound  inflorescences,  the  small  racemes  in 
pairs,  each  pair  partly  included  in  a  sheathing  spathe. 

An  allied  genus,  Anatherum  Beauv.,  is  represented  by  a  single 
species,  A.  zizanioides  (L.)  Hitchc.  and  Chase  (Andropogon  muri- 
catus  Eetz. ;  Vetiveria  zizanioides  Nash).  This  Old  World  grass  is 
frequently  cultivated  in  tropical  America  for  hedges  and  for  the 
aromatic  roots,  which  are  used  for  making  screens  and  mats  to  per- 
fume the  air  of  houses.  These  roots  readily  impart  perfume  when 
wet.  The  grass  is  called  vetiver,  khus-khus,  and  khas-khas.  It  has 
escaped  from  cultivation  in  Louisiana.  Vetiver  is  a  robust  grass 
with  a  large  erect  panicle,  the  slender  whorled  branches  ascending, 
naked  at  the  base,  the  awnless  spikelets  muricate. 

1Bull.  Misc.  Inf.  Kew  1906:  297.     1906. 


264  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


FIG.    160. — Big   bluestem,   Andropogon    furcatus.      Plant,    X    \  ',    pair   of   spikelets   with 

joint  of  rachis,    X    5. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XIX. 


BLUESTEM  (ANDROPOGON  FURCATUS). 

Jlocky  fcanks  of  the  Pot  cmac.    A  valuable  forage  grass  on  the  prairies  of  the  Mississippi  Valley. 


Bui.  772,  U.  S.  Dept.  of  Agriculture. 


PLATE  XX. 


GAMA  GRASS  (TRIPSACUM  DACTYLOIDES).     NEAR  WASHINGTON,  D.  C. 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  265 


FIG.  161. — Andropogon  saccharoides.     riant,   X    J  ;  pair  of  spikelets  with  joint  of  rachis 
(at  left),  the  pedicellate  spikelet  showing  a  little  at  right,    X    5. 


266  BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 

Arthraxon  Beauv.,  Ess.  Agrost.  111.  1812.  Type  species,  A. 
ciliaris  Beauv.  This  Old  World  genus  is  represented  in  North 
America  by  A.  qiwrtwiwms  (A.  Eich.)  Nash,  introduced  into  Ja- 
maica and  Guadaloupe,  and  by  A.  ciliaris  cryptatherus  Hack.,  estab- 
lished in  the  vicinity  of  Washington,  D.  C.  The  latter  is  a  creeping 
slender  grass  with  thin  cordate-lanceolate  blades,  the  inflorescence 
of  several  slender  racemes  in  a  cluster. 

133.  HOLCUS   L. 
(SorgJmm  Pers.) 

Spikelets  in  pairs,  one  sessile  and  fertile,  the  other  pedicellate, 
sterile  but  well  developed,  usually  staminate,  the  terminal  sessile 
spikelet  with  two  pedicellate  spikelets. 

Annual  or  perennial,  tall  or  moderately  tall  grasses,  with  flat 
blades  and  terminal  panicles  of  1  to  5  jointed  tardily  disarticulating 
racemes.  Species  about  six,  one  Mexican,  the  others  in  the  Old 
World ;  two  cultivated  or  introduced  into  America. 

Type  species:  Holcus  sorghum  L. 

Holcus  L.,  Sp.  PI.  1047,  1753;  Gen.  PL,  ed.  5,  469.  1754.  Linnreus  describes 
seven  species,  H.  sorghum,  H.  saccharatus,  H.  halepensis,  H.  lanatus,  H.  odo- 
ratus,  H.  laxus,  and  H.  striatus.  The  selection  of  the  type  species  is  of 
particular  importance  in  this  genus,  because  it  affects  the  generic  name  of 
the  group  containing  the  cultivated  sorghums.  The  first  three  of  the  original 
seven  species  were  segregated  from  the  others  in  1763  by  Adanson,  who  applied 
to  them  the  old  name  sorghum,  used  by  Bauhin  and  other  pre-Linnsean  authors 
for  the  cultivated  sorghums.  This  name  was  accepted  by  most  of  those  subse- 
quent authors  who  recognized  the  group  as  a  genus  distinct  from  Andropogon, 
and  as  a  subgeneric  name  by  those  who  held  it  to  be  a  subgenus  of  Andropogon. 
Of  the  remaining  four  of  the  original  seven  species  of  Holcus  all  but  H.  lana- 
tus  were  early  assigned  to  other  genera,  leaving  H.  lanatus  in  possession  of  the 
generic  name  and  in  effect  making  this  residual  species  the  type  of  the  genus. 
Linnaeus,  however,  in  all  the  editions  of  the  Genera  Plantarum  and  in  the 
Hortus  Cliffortianus  and  the  Hortus  Upsaliensis  used  the  name  Holcus  for 
sorghum  only.  The  description  and  the  synonymy  in  all  cases  apply  only  to  the 
first  three  of  the  seven  species  included  in  the  Species  Plantarum.  Moreover,  in 
all  the  editions  of  the  Genera  Plantarum  Linnaeus  cites  "  Sorgum  Mich."  While 
Micheli1  gives  no  description  or  figure  of  the  genus,  we  know  from  Bauhin 
and  others  that  Sorgum  or  Sorghum  was  in  common  use  for  the  group  in 
question.  Linna?us  uses  the  old  name  Sorghum  for  the  trivial  or  specific  name 
of  the  first  species,  and  cites  Sorghum  of  Bauhin  as  a  synonym.  It  is  clear 
that  the  Holcus  of  Linna?us  is  the  old  Sorghum,  the  other  four  diverse  species 
(which  do  not  agree  with  the  generic  descriptions  in  any  of  the  works  cited), 
evidently  being  appended  for  want  of  a  place  to  put  them.  According  to  the 
American  Code  the  genera  of  Lirmseus's  Species  Plantarum  are  to  be  typified 
through  citations  given  in  his  Genera  Plantarum  of  1754.  The  reference  to 
Micheli,  the  use  of  sorghum  as  a  specific  name,  and  the  descriptions  all  point 
to  H.  sorghum  as  the  type  of  the  genus  Holcus.  Holcus  lanatus  is  now  referred 
to  Notholcus,  H.  odoratus  to  Torresia  (Hierochloe,  Savastana),  H.  laxus  to 
Uniola,  and  H.  striatus  to  Sacciolepis.  By  many  authors  the  genus  Holcus  as 
here  understood  is  included  under  Andropogon. 

Blumenbachia  Koel.,  Descr.  Gram.  28.  1802.  A  single  species,  "  B.  halep- 
pensis."  based  on  "  Holcus  Haleppensis  Linn."  is  included. 

Sorghum  Pers.,  Syn.  PI.  1 :  101.  1805.  Four  species  are  included.  Holcus 
sorghum  L.,  upon  which  £.  vulgare  Pers.  is  based,  is  taken  as  the  type. 

.  Plant.  Gen.  35.     1729. 


GENERA   OF   GRASSES   OF    TIIK    TXITFJ)   STATES.  267 

Holcus  sorghum  L.  (Andropogon  sorghum  Brot. ;  Sorghum  vul- 
gare  Pers.)  has  been  cultivated  from  prehistoric  times1  for  the  seed, 
which  has  been  used  for  food,  for  the  sweet  juice,  and  for  forage.  In 
the  United  States  it  is  cultivated  under  the  general  name  of  sorghum 
or  sorgo.  There  are  many  races  and  varieties,  the  chief  of  which  are 
sorgo,  kafir,  milo,  broom  corn,  shallu,  kaoliang,  and  durra.  Sorgo 
includes  the  varieties  with  sAveet  juice,  these  varieties  often  being 
known  collectively  as  saccharine  sorghums. 

In  this  country  sorgo  is  cultivated,  chiefly  in  the  region  from  Kan- 
sas to  North  Carolina,  for  the  juice  which  is  made  into  sirup  and 
for  foliage  which  is  used  for  fodder  in  the  Southern  States,  especially 
in  the  region  from  Kansas  to  Texas,  where  it  is  often  called  "cane." 
The  other  races  of  sorghum  are  often  classed  together  as  non- 
saccharine  sorghums.  The  large  panicles  of  one  race,  broom  corn, 
grown  especially  in  Illinois,  furnish  the  material  for  brooms.  The 
other  races  are  used  for  forage  or  for  the  seed,  which  is  used  for 
feed.  Kafir,  milo,  and  a  recently  introduced  variety,  feterita,  are 
of  especial  value  in  the  southern  part  of  the  Great  Plains  and  other 
semiarid  regions  where  dry-land  farming  is  practiced.  Kafir,  or 
Kafir  corn,  is  a  rather  low  form  with  compact  cylindric  heads  and 
awnless  spikelets.  Milo,  or  milo  maize,  is  a  usually  taller  form,  with 
ovate  heads,  a  straight  or  recurved  peduncle,  awned  spikelets,  and 
larger  seeds.  Durra  differs  from  milo  in  having  densely  pubescent 
grayish  or  greenish  glumes  (instead  of  brown  or  black  and  slightly 
pubescent),  and  strongly  flattened  seeds.  Some  of  these  forms  are 
called  Egyptian  corn,  chicken  corn,  and  Jerusalem  corn.  The  name 
chicken  corn  should  be  restricted  to  a  variety  spontaneous  in  Louisi- 
ana and  Mississippi  (Holcus  sorghum  drummondii  (Nees)  Hitchc., 
Andropogon  drumm-ondii  Nees,  A.  sorghum  drummondii  Hack.). 
A  recently  introduced  variety,  IIolcus  sorghum  sudanensis  (Piper) 
Hitchc.  (Andropogon  sorghum  sudanensis  Piper),  is  now  extensively 
cultivated  for  hay  in  the  semiarid  regions  under  the  name  of  Sudan 
grass.  This  is  a  rather  slender  annual,  6  to  9  feet  tall,  the  panicle 
open  and  spreading.  The  absence  of  rhizomes  shows  its  affinity  to 
sorgo.  Tunis  grass  is  an  allied  variety  (IIolcus  sorghum  exiguus 
(Forsk.)  Hitchc.,  IIolcus  exiguus  Forsk.,  Andropogon  sorghum  ex- 
iguus Piper)  that  has  been  tried  in  our  Southern  States. 

The  second  species  of  Holcus  found  in  the  United  States  is  H. 
halepensis  L.  (fig.  162),  known  as  Johnson  grass.  This  is  a  perennial 
with  stout  creeping  rhizomes.  The  panicle  is  open  and  spreading, 
the  spikelets  awned  or  awnless.  Johnson  grass  is  not  so  tall  as  the 
open-panicled  forms  of  sorghum,  being  usually  3  to  5  feet  tall,  and 

1  For  a  history  and  classification  of  sorghum,  see  Ball,  IT.  S.  I'epl.  Aj;r.f  Bur.  Tl.  Ind. 
Bull.  175.  1910. 


268  BULLETIN   772,   U.    S.    DEPARTMENT   OF   AGRICULTURE. 


FIG.  102. — Johnson  grass,  Holcus  halcpcnuis.     Plant,   X   B  ;  two  views  of  terminal  raceme, 
one  of  the  pedicellate   spikelets   fallen,    X    5. 


GENERA  OF   GRASSES   OF   THE   UNITED  STATES.  269 

has  narrower  blades  than  plants  of  sorghum  of  the  same  height. 
The  characteristic  difference  is  the  presence  of  the  creeping  rhizomes 
in  the  former.  Johnson  grass  is  a  native  of  the  Mediterranean 
region,  but  is  now  widely  distributed  in  the  warmer  parts  of 
America.  In  the  United  States  it  is  common  throughout  the 
South,  where  it  is  often  a  troublesome  weed.  It  is  an  ex- 
cellent and  much-used  forage  grass,  but  the  difficulty  of  eradicating 
it  from  ground  that  it  has  once  occupied  offsets  its  forage  value. 
Johnson  grass  has  become  an  especially  pernicious  weed  on  the 
Black  Lands  of  Alabama  and  Texas.1 

The  sorghums  and  Johnson  grass  sometimes  produce  hydrocyanic 
acid  in  sufficient  abundance,  especially  in  second  growth,  to  poison 
grazing  animals. 

134.    SORGHASTETJM  Nash. 

Spikelets  in  pairs,  one  nearly  terete,  sessile,  and  fertile,  the  other 
wanting,  only  the  hairy  pedicel  being  present;  glumes  coriaceous, 
brown  or  yellowish,  the  first  hirsute,  the  edges  inflexed  over  the 
second;  sterile  and  fertile  lemmas  thin  and  hyaline,  the  latter  ex- 
tending into  a  usually  well-developed  bent  and  twisted  awn. 

Perennial,  erect,  rather  tall  grasses,  with  narrow  flat  blades  and 
narrow  terminal  panicles  of  one  to  few  jointed  racemes.  Species 
about  10  in  the  warmer  parts  of  the  Western  Hemisphere,  and  a 
few  in  Africa;  3  species  in  the  United  States  east  of  the  Rocky 
Mountains. 

Type  species :  Andropogon   avenaceus   Michx. 

Poranthera  Raf.,  Bull.  Bot.  Seringe  1:  221,  1830,  not  Rudge,  1811.  "Andro- 
pogon nutans  -[L.]  et  ciliatus  [Ell.])"  are  cited.  These  names  apply  to  the 
same  species,  Sorghastrum  nutans  (L.)  Nash. 

Sorghastrum  Nash,  in  Britton,  Man.  71.  1901.  Only  one  species  described. 
S.  avenaceum  (Michx.)  Nash. 

Chalcoelytrum  Lunell,  Amer.  Midi.  Nat.  4 :  212.  1915.  The  name  proposed  to 
replace  Sorghastrum  Nash,  which,  being  built  on  Sorghum,  is  considered  unde- 
sirable. 

The  units  of  the  inflorescence  are  racemes  reduced  to  one  or  two 
joints,  or  in  Sorghastrum  nutans  sometimes  four  or  five.  The  slen- 
der, villous  rachis  disarticulates  at  the  top  of  each  joint,  the  spikelets 
falling  with  two  villous  stalks  attached,  one  the  rachis  joint,  the 
other  the  pedicel  of  the  obsolete  sterile  spikelet.  The  articulation  is 
more  or  less  oblique,  leaving  a  bearded  blunt  callus  or,  in  some  South 
American  species,  a  long,  sharp  callus.  In  S.  nutans  the  racemes  not 
infrequently  occur  in  pairs  with  a  sessile  spikelet  in  the  fork,  that 
is,  the  pedicel  of  the  sterile  spikelet  of  the  lowest  joint  has  been  re- 
placed by  a  short  raceme  of  one  or  two  joints. 

1  For  methods  of  eradication,  see  Cates  and  Spillman,  U.  S.  Dept.  Agr.,  Farmers'  Bull. 
279.  1907. 


270  BULLETIN    772,    U.    S.    DEPARTMENT   OF   AGRICULTURE. 

The  commonest  species  of  the  genus  in  the  United  States  is  Sor- 
ghastrum  nutans  (L.)  Nash  (fig.  163),  sometimes  called  Indian  reed 
or  Indian  grass.  This  is  a  tall,  erect  grass  with  handsome  bronze- 
colored  panicles  as  much  as  a  foot  long,  the  awns  about  half  an  inch 
long,  the  anthers  brilliant  yellow.  The  species  is  found  in  prairies 
and  open  woods  throughout  the  eastern  United  States  and  south- 
westward  to  Arizona  and  Mexico.  It  is  a  common  constituent  of 
prairie  hay  in  the  eastern  part  of  the  Great  Plains  region. 

Two  other  species  are  found  in  the  Southern  States,  both  with 
awns  about  an  inch  long,  Sorghaetrum  elliottii  (C.  Mohr)  Nash,  with 
pedicels  villous  only  at  the  very  tip,  and  S.  secundum  (Chapm.)  Nash, 
with  a  one-sided  panicle  and  pedicels  villous  along  the  upper  portion. 

135.  RHAPHIS  Lour. 

Spikelets  in  threes,  one  sessile  and  perfect,  the  other  two  pedicellate 
and  sterile,  or  sometimes  a  pair  below,  one  fertile  and  one  sterile; 
fertile  spikelet  terete,  the  glumes  coriaceous;  sterile  and  fertile 
lemmas  thin  and  hyaline,  the  latter  long-awned. 

Perennial  grasses,  or  our  species  annual,  with  open  panicles,  the 
three  spikelets  (reduced  racemes)  borne  at  the  ends  of  long,  slender, 
naked  branches.  Species  about  20,  all  in  the  tropical  regions  of  the 
Eastern  Hemisphere  except  the  1  found  in  the  southern  United  States. 

Type  species:  Rhaphis  trivialis  Lour. 

Rhaphis  Lour.,  Fl.  Cochinch.  553.  1790.  Only  one  species  described,  which 
is  the  same  as  Andropojion-  (idculatus  Retz.  Some  authors  have  thought  the 
name  Rhaphis  was  invalidated  by  the  earlier  Rhapis  L.  f.  (1789),  a  genus  of 
palms.  The  names  have  a  different  derivation  and  a  different  pronunciation, 
and  the  one  does  not  invalidate  the  other. 

Pollinia  Spreng.,  Pugill.  2:  10,  1815,  not  Pollinia  Trin.,  1832.  Type  species, 
P.  gryllus  Spreng.  (Andropogon  gryllus  L. ).  Several  species  are  described, 
but  the  generic  characters  are  given  under  the  first  species. 

Centrophorum  Trin.,  Fund.  Agrost.  106,  pi.  5.  1820;  Type  species,  C.  chincnse 
Trin.  (Andropoyon  (iciculfttu*  Retz.),  the  only  one  described. 

Chrysopogon  Trin.,  Fund.  Agrost.  187.  1820.  Type  species,  Andropogon 
gryllus  L.  Two  species  are  mentioned,  C.  gryllus  and  Ct  aciculatus,  but  an 
illustration  of  the  first  is  cited. 

The  only  species  occurring  in  the  United  States  is  Rhaphis  pauci- 
flora  (Chapm.)  Nash  (fig.  164),  an  annual  found  in  Florida  and 
Cuba.  This  has  the  aspect  of  a  species  of  Stipa,  the  spikelets  with 
their  long  awns  and  barbed  callus  resembling  the  fruit  of  Stipa 
spartea.  The  long  slender  branches  of  the  few-flowered  panicle  bear 
a  terete,  brown,  sessile  fertile  spikelet  and  two  slender  sterile  pedicels, 
each  with  a  slender  glume.  The  peduncle  disarticulates  by  a  long 
oblique  line  through  the  thickened  villous  end,  the  portion  separating 
with  the  spikelet  being  densely  brown-villous,  this  forming  a  long 
sharp  callus.  The  glumes  are  coriaceous  and  at  maturity  separate 
somewhat,  the  spikelet  gaping  at  the  apex.  The  palea  is  present,  but 


GENERA   OF   GRASSES   OF   THE   UNITED   STATES.  271 


FIG.   163. — Indian   grass,  *  Sorghastrum  nutans.     Plant,    X    i;   spikelet   with  pedicel   at 
left  and  rachis  joint  at  right,   X  5. 


272  BULLETIN    772,   U.    S.    DKI'AIITM  KNT   OF   AGRICULTURE. 


Fio.    164. — Rhavhis  jHiucijIora.      Plant  with   <>M    splkHK   still    jiUiirln'd    to  roots,    X 
fruiting    fertile    spikelet,    X    5. 


GENERA  OF  GRASSES  OF  THE  UNITED  STATK-.  273 

much  shorter  than  the  very  thin  sterile  and  fertile  lemmas.  The 
awn  is  about  6  inches  long,  twisted  and  bent.  The  species  before 
maturity  furnishes  forage  on  the  grassy  pinelands  of  southern 
Florida. 

136.  HETEBOPOGON  Pers. 

Spikelets  in  pairs,  one  sessile,  the  other  pedicellate,  both  of  the 
lower  few  to  several  pairs  staminate  or  neuter,  the  remainder  of  the 
sessile  spikelets  perfect,  terete,  long-awned,  the  pedicellate  spikelots, 
like  the  lower,  staminate,  flat,  conspicuous,  awnless;  glumes  of  the 
fertile  spikelet  equal,  coriaceous,  the  first  brown-hirsute,  infolding 
the  second  ;  lemmas  thin  and  hyaline,  the  fertile  one  narrow,  extend- 
ing into  a  strong  bent  and  twisted  brown  awn  ;  palea  wanting;  glumes 
of  the  staminate  spikelet  membranaceous,  the  first  green,  faintly  many 
nerved,  asymmetric,  one  subrnarginal  keel  rather  broadly  winged, 
the  other  wingless,  the  margins  inflexed,  the  second  glume  narrower, 
symmetric  ;  lemmas  hyaline  ;  palea  wanting. 

Annual  or  perennial,  often  robust  grasses,  with  flat  blades  and  soli- 
tary racemes  terminal  on  the  culms  and  branches  ;  rachis  slender,  the 
lower  part,  bearing  the  pairs  of  staminate  spikelets,  continuous,  the 
remainder  disarticulating  obliquely  at  the  base  of  each  joint,  the  joint 
forming  a  sharp  barbed  callus  below  the  fertile  spikelet,  the  pedicel- 
late spikelet  readily  falling,  its  pedicel  remaining,  obscured  in  the 
hairs  of  the  callus.  Species  about  seven,  in  the  warmer  regions  of 
both  hemispheres;  two  in  the  United  States,  from  Florida  to  Arizona. 


Typo  spocios  :  Ifftnrop'jf/rm  yJnl<"r  Pers. 

Heteropogon  Pers.,  Syn.  PI.  2  :  533.  1807.  Persoon  describes  two  species,  H. 
ylaber,  of  which  he  gives  as  synonyms  Andropoyon  allioni  DC.  and  A.  cf/n- 
tortus  All.,  and  H.  hirtun,  of  which  ho  gives  as  a  synonym  Andropoyon  con- 
tortiiH  L.  The  first  ;li<-  type. 

Spirotheros  Raf.,  Bull.  Hot.  Serins  1  :  221.  1830.  A  single  species,  "  Stipa 
melanocarpa,  Muhl.,  Andropoyon  nwianwaritus  Ell.,"  is  given. 


The  two  species  in  the  United  States  are  Heteropogon  contortus 
(L.)  Beauv.  (fig.  105),  a  perennial,  1  to  3  feet  tall,  the  first  glume 
of  the  staminate  spikelets  papillose-pilose,  sometimes  sparsely  so, 
anrl  77.  melo/nacoppus  (Ell.)  Benth.,  an  annual,  4  to  7  feet  tall  and 
often  much  branched,  the  first  glume  of  the  staminate  spikelets  bear- 
ing a  row  of  glands  along  the  back.  The  first  species  is  found  in 
rocky  places  from  Texas  to  Arizona.  The  second  is  found  in  Florida, 
Georgia,  and  Alabama;  also  in  Arizona.  The  oil  glands  on  the  in- 
florescence of  the  latter  give  the  plant  an  odor  like  that  of  citronella 
oil. 

Heteropogon  contortus  is  an  important  forage  grass  but  does  not 
extend  far  into  the  United  States.  In  the  Hawaiian  Islands,  where 
it  is  called  pili,  it  is  an  important  range  grass  on  the  drier  areas.  It 
was  used  by  the  natives  to  thatch  their  grass  huts.  The  mature  fruits 
are  injurious  to  sheep. 

97769°—  19—  Bull.  772  -  18 


274          BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 


FIG.  165.— Heteropogon  contortus.    Plant,  X  J  ;  fruiting  fertile  spikelet,  X  5. 


GENERA  OF   GRASSES   OF  THE   UNITED   STATES.  275 

137.  TRACHYPOGON  Nees. 

Spikelets  in  pairs,  along  a  slender  continuous  rachis,  one  nearly 
sessile,  staminate,  awnless,  the  other  pedicellate,  perfect,  long-awned ; 
the  pedicel  of  the  perfect  spikelet  obliquely  disarticulating  near  the 
base,  forming  a  sharp  barbed  callus  below  the  spikelet;  first  glume 
firm-membranaceous,  rounded  on  the  back,  several-nerved,  obtuse; 
second  glume  firm,  obscurely  nerved ;  fertile  lemma  narrow,  extend- 
ing into  a  stout  twisted  and  bent  or  flexuous  awn;  palea  obsolete; 
sessile  spikelet  persistent,  as  large  as  the  fertile  spikelet  and  similar 
but  awnless. 

Perennial,  moderately  tall  grasses,  with  terminal  spikelike  racemes, 
these  single  or  clustered.  Species  about  seven,  Mexico  to  South 
America,  one  extending  into  the  southwestern  United  States. 

Type  species :  Andropogon  montufari  H.  B.  K. 

Trachypogon  Nees,  Agrost.  Bras.  341.  1829.  The  first  of  the  13  species  de- 
scribed, T.  montufari,  based  on  Andropogon  montufari,  is  selected  as  the  type. 
The  first  five  species  are  all  that  are  now  retained  in  Trachypogon. 

Our  only  species  is  Trachypogon  montufari  (H.  B.  K.)  Nees  (fig. 
166),  found  in  southern  Arizona  and  southwestern  New  Mexico,  an 
erect  slender  perennial  with  solitary  racemes,  the  feathery  awns 
about  1|  inches  long.  It  is  an  important  constituent  of  the  grazing 
areas  of  Central  and  South  America. 

138.  ELYONTTRUS  Humb.  and  Bonpl. 

Spikelets  in  pairs  along  a  somewhat  tardily  disarticulating  rachis, 
the  joints  and  pedicels  thickened  and  parallel,  the  sessile  spikelets 
appressed  to  the  concave  side,  the  pedicellate  spikelet  staminate, 
similar  to  the  sessile  one,  both  awnless,  the  pair  falling  with  a  joint 
of  the  rachis;  first  glume  firm,  somewhat  coriaceous,  depressed  on 
the  back,  the  margins  inflexed  around  the  second  glume,  a  line  of 
balsam  glands  on  the  marginal  nerves,  the  apex  entire  and  acute 
or  acuminate,  or  bifid  with  aristate  teeth;  second  glume  similar  to 
the  first ;  sterile  and  fertile  lemmas  thin  and  hyaline ;  palea  obsolete. 

Erect,  moderately  tall  perennials,  with  solitary  spikelike,  often 
woolly  racemes.  Species  about  15,  in  the  warmer  regions  of  both 
hemispheres;  two  species  extending  into  our  Southern  States. 

Type  species :  Elyonurus  tripsacoides  Humb.  and  Bonpl. 

Elyonurus  Humb.  and  Bonpl.,  Willd.  Spec.  PI.  4 :  941.  1806.  Only  one  species 
is  described. 

Elyonurus  tmpsacoides  (fig.  167),  with  inconspicuously  hairy 
spikes,  extends  from  Florida  to  Texas,  and  E.  'barbiculmis  Hack., 
with  conspicuously  woolly  spikes,  is  found  from  western  Texas  to 
Arizona.  The  species  of  Elyonurus  are  important  grazing  grasses  in 
the  savannas  and  plains  of  tropical  America. 


276          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  1G6. — Tracliypoyon  montufari.    Plant,  X  i  ;  fruiting  fertile  spikelet,  X  5. 


GENERA  OF  GRASSES  OF  THE  UNITED  STATES. 


277 


FIG.  167. — Elyonurus  tripsacoides.     Plant,  X  J  ;  two  views  of  a  pair  of  spikelets  with  a 

joint  of  the  rachis,  X  5. 


278  BULLETIN   772,   U.   S.   DEPARTMENT   OF  AGRICULTURE. 

139.  MANISURIS   L. 
(Rottbocllia  L.  f.) 

Spikelets  awnless,  in  pairs  at  the  nodes  of  a  thickened  articulate 
rachis,  one  sessile  and  fertile,  the  other  pedicellate  and  sterile,  the 
pedicel  thickened  and  appressed  to  the  rachis,  the  sessile  spikelet 
fitting  closely  against  the  rachis,  forming  a  cylindric  or  subcylindric 
spike;  glumes  obtuse,  awnless,  the  first  coriaceous,  fitting  over  the 
hollow  containing  the  spikelet,  the  second  less  coriaceous  than  the 
first;  sterile  lemma,  fertile  lemma,  and  palea  thin  and  hyaline,  in- 
closed within  the  glumes;  pedicellate  spikelet  reduced,  often  rudi- 


Perennial  slender,  moderately  tall,  or  tall  grasses,  with  usually 
numerous  smooth  cylindric  or  flattened  spikes,  single  on  the  culms 
and  branches.  Species  about  30,  in  the  warm  regions  of  both  hemi- 
spheres ;  5  in  the  southern  United  States. 

Type  species:  Manisuris  myuros  L. 

Manisuris  L.,  Mant.  PI.  2  :  164.     1771.     Only  one  species  described. 

Rottboellia  L.  f.,  Nov.  Gram.  Gen.  22,  pi.  1,  1779  (Amoen,  Acad.  10.  1790), 
not  Scop.,  1777.  In  a  note  appended  to  the  description  of  the  genus  is  the 
statement,  "  Hue  pertinent  Aegilops  Incurvata  &  Exaltata  S.  N.,  p.  762,  aeque 
ac  Panicum  Dimidiatum  S.  N.,  p.  90."  The  second  species,  being  the  one  illus- 
trated, is  the  type. 

Stegosia  Lour.,  Fl.  Cochinch.  1:  51.  1790.  Type,  S.  cochinchinensis  Lour., 
the  only  species  described. 

Hemarthria  R.  Br.,  Prodr.  FL  Nov.  Holl.  207.  1810.  Two  species  described, 
H.  compressa  and  H.  uncinata.  The  first  species,  based  upon  Rottboellia  com- 
pressa  L.  f.,  is  chosen  as  the  type. 

Lodicularia  Beauv.,  Ess.  Agrost.  108,  pi.  21,  f.  6.  1812.  A  single  species  is 
included,  L.  fasciculata,  based  on  Rottboellia  fasciculata  Desf.  (R.  fasciculata 
Lam.  evidently  intended). 

Coelorhachis  Brongn.,  in  Duperr.  Bot  Toy.  Coquille  64.  1829.  The  type  is 
Aegilops  muricata  Retz.,  on  which  is  based  Coelorhachis  muricata,  the  only 
species  described. 

The  species  of  Manisuris  found  in  the  United  States  are  nowhere 
abundant  and  are  of  little  economic  importance,  though  they  may 
furnish  some  forage.  Manisuris  fasciculata  (Lam.)  Hitchc.  has 
flattened  spikes.  The  other  three  species  have  cylindric  spikes. 
In  these  the  first  glume  is  variously  marked,  being  somewhat  pitted 
in  M.  cylindrica  (Michx.)  Kuntze  (fig.  168),  tessellate  in  M.  tessel- 
lata  (Steud.)  Scribn.,  and  transversely  wrinkled  in  M.  rugosa  (Nutt.) 
Kuntze. 

140.  RYTILIX  Raf. 
(Hackelochloa  Kuntze,  Manisuris  of  authors.) 

Spikelets  awnless,  in  pairs,  the  rachis  joint  and  pedicel  grown 
together,  the  two  clasped  between  the  edges  of  the  globose  alveolate 
first  glume  of  the  sessile  spikelet;  pedicellate  spikelet  conspicuous, 
staminate. 

A  much-branched  annual  with  flat  blades,  the  numerous  spikes 
single  and  more  or  less  inclosed  in  the  sheathing  bract,  these  some- 


GENERA  OF   GRASSES  OF  THE  UNITED   STATES. 


279 


PIG.  168. — Manisuris  cylindrica.  Plant,  X  £  ;  sessile  spikelet  and  joint  of  rachis,  x  5  ; 
joint  of  rachis  with  sterile  pedicel  and  rudimentary  spikelet,  the  fertile  spikelet  at 
right.  X  5. 


280          BULLETIN   772,   TJ.   S.   DEPARTMENT  OF  AGRICULTURE. 


what  clustered  in  the  axils  of  the  foliage  leaves.     Species  one,  in 
the  tropical  regions  of  the  world. 

Type  species:  Manisuris  granularis  Swartz. 

Rytilix  Raf.,  Bull.  Bot.  Seringe  1:  219.  1830.  Rafinesque  cites  "Manisuris 
granularis  et  Myurus  Auct"  and  lists  one  species  Rytilix  glandulosa.  The  first 
species  cited  is  chosen  as  the  type. 

Hackelochloa  Kuntze,  Rev.  Gen.  PI.  2 :  776.  1891.  Kuntze  restores  Manisuris 
to  its  Linnsean  sense  and,  overlooking  Rytilix  Raf.,  proposes  Hackelochloa  for 

Manisuris  Swartz,  with  H.  granu- 
laris, based  on  Cenchrus  granularis, 
as  the  type. 

Rytilix  granularis  (L.) 
Skeels  (fig.  169)  is  a  tropical 
weed  which  extends  into  the 
United  States  from  Florida 
to  Arizona.  The  little  pitted 
globose  spikelets  are  very  char- 
acteristic. 


FIG.  169. — Rytilix  granularis.     Plant,   X   *  ;  a  single  raceme,   X   2  ;  two  yiews  of  a  pair 
of  spikelets  with  joint  of  rachis  and  pedicel  grown  together,   X   5. 

14.  TRIPSACEAE,  THE  CORN  TRIBE. 

141.  TBIPSACUM  L. 

Spikelets  unisexual ;  staminate  spikelets  2-flowered,  in  pairs  on  one 
side  of  a  continuous  rachis,  one  sessile,  the  other  sessile  or  pedicellate, 
similar  to  those  of  Zea,  the  glumes  firmer ;  pistillate  spikelets  single 


GENERA  OF   GRASSES   OF  THE   UNITED   STATES.  281 

and  on  opposite  sides  at  each  joint  of  the  thick,  hard  articulate  lower 
part  of  the  same  rachis,  sunken  in  hollows  in  the  joints,  consisting  of 
one  perfect  floret  and  a  sterile  lemma ;  first  glume  coriaceous,  nearly 
infolding  the  spikelet,  fitting  into  and  closing  the  hollow  of  the 
rachis;  second  glume  similar  to  the  first  but  smaller,  infolding  the 
remainder  of  the  spikelet;  sterile  lemma,  fertile  lemma,  and  palea 
very  thin  and  hyaline,  these  progressively  smaller. 

Robust  perennial  grasses,  with  usually  broad  flat  blades  and 
monoecious  terminal  and  axillary  inflorescences  of  1  to  3  spikes,  the 
pistillate  part  below,  breaking  up  into  bony,  seedlike  joints,  the 
staminate  above  on  the  same  rachis,  deciduous  as  a  whole.  Species 
about  seven,  all  American,  extending  from  the  middle  United  States 
to  northern  South  America ;  three  species  in  the  United  States. 

Type  species :  Coix  dactyloides  L. 

Tripsacum  L.,  Syst.  Nat.,  ed.  10,  2:  1261.  1759.  Type  the  first  of  the  two 
species  described,  T.  dactyloides,  based  on  Coix  dactyloides  L.,  and  T.  hermaph- 
roditum.  The  second  species,  based  on  "  Cenchrus  2,  Brown.  Jam.  367,"  is 
now  referred  to  Anthephora. 

Dactylodes  Zanoni-Monti ;  Kuntze,  Rev.  Gen.  PI.  2 :  772.  1891.  Two  species 
are  included,  D.  angulatum,  based  on  Coix  angulatus  Mill.,  and  D.  fasciculatum, 
based  on  Tripsacum  fasciculatum  Trin.  Coix  angulatus,  which  is  the  same  as 
Tripsacum  dactyloides,  is  taken  as  the  type. 

The  common  species  in  the  United  States  is  Tripsacum  dactyloides 
(PL  XX;  fig.  170),  a  robust  perennial,  3  to  6  feet  tall,  with  broad 
blades,  the  terminal  spikes  mostly  in  threes,  the  axillary  spikes  mostly 
solitary.  This  species,  called  gama  grass,  is  found  in  moist  places 
from  Connecticut  to  Texas  and  Florida.  It  is  a  good  forage  grass, 
but  is  usually  not  abundant  enough  to  be  of  much  importance.  A 
second  species,  T.  floridanum  Porter,  with  narrow  blades,  is  found  in 
southern  Florida,  and  a  third  species,  T.  lemmoni  Yasey,  with  pilose 
lower  sheaths,  is  found  in  Arizona. 

142.  EUCHLAENA  Schrad. 

Staminate  spikelets  as  in  Zea;  pistillate  spikelets  single,  on  oppo- 
site sides,  sunken  in  cavities  in  the  hardened  joints  of  an  obliquely 
articulate  rachis,  the  indurate  first  glume  covering  the  cavity;  sec- 
ond glume  membranaceous,  the  lemmas  hyaline.  Spikes  infolded  in 
foliaceous  bracts  or  husks,  2  to  several  of  these  together  inclosed  in 
the  leaf  sheaths. 

The  one  species  generally  recognized  is  Euchlaena  mexicana 
Schrad.,  a  tall  annual  with  somewhat  the  aspect  of  corn  (Zea  mays), 
a  native  of  Mexico. 

Type  species :  Euchlaena  mexicana  Schrad. 

Euchlaena  Schrad.,  Ind.  Sem.  Hort.  Goettingen.  1832.  Only  one  species 
described.  The  specimen  was  collected  by  Dr.  Miihlenfordt  in  Mexico. 

The  genus  is  little  known.  Several  species  have  been  proposed, 
but  they  are  doubtfully  distinct  from  Euchlaena  mexicana.  An  un- 


282          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  170. — Gama  grass,  Tripsacum  daetyloides.  Rhizome,  leaves,  and  inflorescence,  X  I  ; 
pistillate  spikelet  and  joint  of  rachis,  X  5  ;  pair  of  staminate  spikelets  with  joint  of 
rachis,  X  5. 


GENEKA  OF  GRASSES  OF  THE  UNITED   STATES.  283 

described  species  from  Mexico  is  a  perennial  with  simple  culms  and 
creeping  rhizomes.  A  form  which  is  supposed  to  be  the  original 
E.  mexicana  is  cultivated  occasionally  in  our  Southern  States,  where 
it  is  known  as  teosinte  (fig.  171).  This  is  a  tall,  stout  grass,  usually 
branching  at  the  base  and  forming  large  clumps.  The  tassel  is  like 
that  of  corn,  and  the  fascicles  of  spikes,  inclosed  in  husks  with  the 
long  styles  or  silk  hanging  from  the  apex,  bear  a  superficial  resem- 
blance to  the  ears  of  corn.  Teosinte  is  cultivated  chiefly  for  soiling. 
It  has  sometimes  been  called  Reana  luxurians  Durieu. 

143.  ZEA  L.,  maize,  Indian  corn. 

Spikelets  unisexual;  staminate  spikelets  2-flowerecl,  in  pairs,  on 
one  side  of  a  continuous  rachis,  one  nearly  sessile,  the  other  pedicel- 
late; glumes  membranaceous,  acute;  lemma  and  palea  hyaline; 
pistillate  spikelets  sessile,  in  pairs,  consisting  of  one  fertile  floret 
and  one  sterile  floret,  the  latter  sometimes  developed  as  a  second, 
fertile  floret;  glumes  broad,  rounded  or  emarginate  at  apex;  sterile 
lemma  similar  to  the  fertile,  the  palea  present;  style  very  long  and 
slender,  stigmatic  along  both  sides  well  toward  the  base. 

A  tall  annual  grass,  with  broad,  conspicuously  distichous  blades, 
monoecious  inflorescences,  the  staminate  flowers  in  spikelike  racemes, 
these  numerous,  forming  large  spreading  panicles  (tassels)  terminat- 
ing the  stems,  the  pistillate  inflorescence  in  the  axils  of  the  leaves, 
the  spikelets  in  8  to  16  or  even  as  many  as  30  rows  on  a  thickened, 
almost  woody  axis  (cob),  the  whole  inclosed  in  numerous  large 
foliaceous  bracts  (husks),  the  long  styles  (silk)  protruding  from  the 
top  as  a  silky  mass  of  threads.  In  the  common  varieties  of  corn  the 
floral  bracts  are  much  shorter  than  the  kernel  and  remain  on  the  cob 
when  the  kernels  are  shelled.1  Species  one. 

Type  species :  Zea  mays  L. 

Zea  L.,  Sp.  PI.  971,  1753;  Gen.  PI.,  ed.  5,  419.  1754.  Zca  mays  is  the 
only  species  described. 

Mays  Tourn.,  in  Gaertn.  Fruct.  and  Sem.  1 :  6,  pi.  1.  1788.  The  single  species, 
If.  zea  Gaertn.,  is  the  same  as  Zea  mays  L. 

Mayzea  Raf.,  Med.  Fl.  2 :  241.  1830.  Two  species  included.  Zea  mays  L.,  on 
which  the  first  species,  M.  ccrealis,  is  based,  is  taken  as  the  type. 

In  the  United  States  Zea  mays  L.  (figs.  172,  173)  is  usually  called 
corn;  in  Europe  and  sometimes  in  America,  especially  in  literature, 
it  is  called  maize.  Corn  is  one  of  the  important  economic  plants  of 
the  world,  being  cultivated  for  food  for  man  and  domestic  animals 
and  for  forage.  It  originated  2  in  America,  probably  on  the  Mexican 
Plateau,  and  was  cultivated  from  prehistoric  times  by  the  early 

1  For  note  on  the  structure  of  the  maize  ear  as  indicated  in  Zea-Euchlaena  hybrids,  see 
Collins,   Journ.  Agr.  Res.  17:   127-135.     1019. 

2  For  a  note  on  the  origin  of  maize,  see  Collins,  Journ.  Washington  Acad.  Sci.  2 :  520. 
1912. 


284  BULLETIN  772,  U.   S.   DEPARTMENT  OF  AGRICULTURE. 


FIG.  171. — Teosinte,  EucJilaena  mcxicana.  Sketch  of  plant,  much  reduced ;  pistillate  in- 
florescence inclosed  in  bract  (a)  and  with  portion  of  bract  removed  (b),  X  1  ;  lateral 
view  of  Joint  of  rachis  and  the  fertile  spikelet  (c),  X  2;  dorsal  view  of  same,  show- 
ing first  glume  (d),  X  2. 


GENERA  OF   GRASSES  OF  THE   UNITED  STATES.  285 


FIG.  172. — Corn,  Zed  mays.     Sketch  of  plant,  much,  reduced. 


286          BULLETIN   772,  U.   S.   DEPARTMENT  OF  AGRICULTURE. 


PIG.  173. — Corn,  Zed  mays.  Tistillate  inflorescence  (ear)  and  two  branches  of  staminate 
inflorescence  (tassel),  X  \  ;  pair  of  pistillate  spikelets  attached  to  rachis  (cob)  with 
mature  caryopses  (grains),  the  second  glume  showing,  X  2;  single  pistillate  spikelet 
soon  after  flowering  showing  first  (at  left)  and  second  glumes  and  young  grain,  X  2  ; 
staminate  spikelet,  X  2. 


GENERA  OF   GRASSES   OF  THE  UNITED  STATES.  287 

races  of  American  aborigines,  from  Peru  to  middle  North  America. 
Several  races  of  corn  are  grown  in  the  United  States,1  the  most  im- 
portant being  dent,  the  common  commercial  field  sort,  flint,  sweet,  and 
pop.  Pod  corn  (Z.  mays  tunicata  Larr.),  occasionally  cultivated  as  a 
curiosity,  is  a  variety  in  which  each  kernel  is  enveloped  in  the 
elongate  floral  bracts.  A  variety  with  variegated  leaves  (Z.  mays 
japonica  Korn.)  is  cultivated  for  ornament. 

144.  Coix  L. 

Spikelets  unisexual;  staminate  spikelets  2-flowered,  in  twos  or 
threes  on  the  continuous  rachis,  the  normal  group  consisting  of  a  pair 
of  sessile  spikelets  with 
a  single  pedicellate 
spikelet  between,  the  lat- 
ter sometimes  reduced 
to  a  pedicel  or  wanting; 
glumes  membranaceous, 
obscurely  nerved; 
lemma  hyaline,  nearly 
as  long  as  the  glumes, 
awnless,  5-nerved ;  palea 
hyaline,  a  little  shorter 
than  the  lemma;  sta- 
mens 3 ;  pistillate  spike- 
lets  3  together,  1  fertile 
and  2  sterile  at  the  base 
of  the  inflorescence ;  fer- 
tile spikelet  consisting 
of  2  glumes,  1  sterile 
lemma,  a  fertile  lemma, 
and  a  palea ;  glumes  sev- 
eral-nerved, hyaline  be- 
low chartaceous  in  the 

Tipper     narrow     pointed  FIG.   174. — Job's-tears,  Coix  lachryma-jobi.     Tipper  por- 

part,     the     first     very 

broad,  infolding  the  spikelet,  the  margins  infolded  beyond  the  2 
lateral  stronger  pair  of  nerves,  the  second  glume  narrower  than  the 
first,  keeled ;  sterile  lemma  about  as  long  as  the  second  glume,  similar 
in  shape  but  a  little  narrower,  hyaline  below,  somewhat  chartaceous 
above;  fertile  lemma  hyaline,  narrow,  somewhat  shorter  than  the 
sterile  lemma ;  palea  hyaline ;  narrow,  shorter  than  the  lemma ;  sterile 
spikelets  consisting  of  a  single  narrow  tubular  glume  as  long  as  the 
fertile  spikelet,  somewhat  chartaceous. 

1  See  Montgomery,  The  Cora  Crops,  15,  1913  :  Sturtevant,  U.  S.  Dept.  Agr.,  Off.  Exp. 
Sta.  Bull.  57.     1899. 


288          BULLETIN   772,   U.   S.   DEPARTMENT  OF  AGRICULTURE. 


Tall  branched  grasses  with  broad  flat  blades,  the  monoecious  in- 
florescences numerous  on  long,  stout  peduncles,  these  clustered  in  the 
axils  of  the  leaves,  each  inflorescence  consisting  of  an  ovate  or  oval, 
pearly  white  or  drab,  beadlike,  very  hard,  tardily  deciduous  involucre 
(much  modified  sheathing  bract)  containing  the  pistillate  lower 
portion  of  the  inflorescence,  the  points  of  the  pistillate  spikelets  and 
the  slender  axis  of  the  staminate  portion  of  the  inflorescence  pro- 
truding through  the  orifice  at  the  apex,  the  staminate  upper  portion 
of  the  inflorescence  2  to  4  cm.  long,  soon  deciduous,  consisting  of 
several  clusters  of  staminate  spikelets.  Species  about  four,  one 
widely  distributed  in  tropical  countries,  the  others  in  the  East  Indies. 

Type  species:    Coix  lacliryma-joM  L. 

Coix  L.,  Sp.  PI.  972,  1753;  Gen.  PI.,  ed.  5,  419.  1754.  Linnaeus  describes 
two  species,  C.  lachryma-jobi  and  C.  dactyloides.  The  reference  in  the  Genera 
Plantarum  (above  cited)  is  to  Tournefort's  plate  302,  which  represents  the  first 
species. 

Coix  lachryma-joli  L.  (fig.  174),  known  as  Job's-tears  and  some- 
times as  Christ's-tears,  is  cultivated  in  all  tropical  countries  for  orna- 
ment and  has  escaped  into  waste  places,  especially  around  dwellings. 
It  is  also  cultivated  in  greenhouses  and  sometimes  in  the  open  in 
warm  temperate  regions.  The  name  Job's-tears  comes  from  the  fan- 
cied resemblance  of  the  fruit  to  tears.  The  fruits,  or  so-called  seeds, 
are  used  for  a  variety  of  purposes,  such  as  beads,  and  for  rosaries. 

LIST  OF  NEW  SPECIES  AND  NEW  NAMES. 


Page. 

Aspris capillaris  (Host)  Hitchc. 

Aira  capillaris  Host 116 

Blepharidachne     benthamiana 

(Hack.)    Hitchc 78 

Munroa  bentMmiana  Hack. 
Bracmaria     cilia  tissima 

(Buckl.)   Chase 221 

Panicum    ciliatissimum 

Buckl. 
Capriola     dactylon     maritima 

(H.  B.  K.)     Hitchc 179 

Cynodon  maritimus  H.  B,  iK. 
Echinochloa    crusgalli    edulis 

Hitchc 238 

Panicum  frumentaceum 
Eoxb.,  1820,  not  Salisb., 
1796. 
Echinochloa  crusgalli  zelayen- 

sis   Hitchc 238 

Oplism enus  zelayensis 

H.  B.  K. 
Epicampes  emersleyi    (Vasey) 

Hitchc 144 

Muhlcnlergia  emersleyi 
Yasey. 


Page. 
Epicampes    subpatens    Hitchc. 

sp.   nov 144 

Fluminea   festucacea    (Willd.) 

Hitchc 38 

Arundo  festucaoca  Willd. 
Muhlenbergia   andina    (Nutt.) 

Hitchc 145 

Calamagrostis  andina 

Nutt. 
Muhlenbergia  montana  (Nutt.) 

Hitchc 146 

Calycodon     montanum 

Nutt. 
Osterdamia  japonica    (Steud.) 

Hitchc 166 

Zoysia  japonica  Steud. 
Pholiurus   incuryatus    (L.) 

Hitchc 106 

Aegilops  incurvata  L. 
Polypogon     lutosus     (Poir.) 

Hitchc 138 

Agrostis  lutosa  Poir. 

Triodia  flaya  (L.)  Hitchc. 76 

Poa  flava  L. 


INDEX. 


[Synonyms  are  in  italic  type.    The  page  numbers  of  the  principal  entries  are  set  in  heavy-face  type.] 


.Page. 

Abola 133 

Acamptoclados 46 

Achyrodes 68 

aureum 68,  69 

Achyrophyton 166 

Adobe  grass 232 

Aegilops  aromaticum 185 

exaltata 278 

hystrix 96 

incurvata 106,  278 

muricata 278 

Aegopogon 169 

cenchroides 169 

tenellus 169,171 

Agraulus 127 

Agropyron 87-89 

cristatum 87 

dasystachyum 87 


repens 87,  88 

saxicola 88 

scribneri 88 

smithii 87,89,94 

spicatum 88 

subvillosum 87 

tenerum 87 

triticeum 87 

Agropyrum 87 

Agrosticula 150 

muralis 150 

Agrostideae 13-15, 121-165 

Agrostis 13, 125, 127-132 

aequivalvis 127, 132 

alba 128 

maritima 129 

vulgaris 129 

algida 132 

alpina 127 

arachnoides 127 

arundinacea 127 

canina 127, 129 

capillaris 129 

crudata 187, 189 

diegoensis 130 

elliottiana 127, 128, 132 

97769°— 19— Bull.  772 19 


Page. 

Agrostis  exarata 129 

microphylla 128 

exigua 128 

hallii 128 

hiemalis: 127, 130 

howellii 128 

indica. 127, 150 

interrupta 127 

juncea 150, 166 

littoralis 138 

lutosa 138 

maritima 129 

matrella 166 

miliacea 127, 158 

minima 127 

palustris 128, 129 

paradoxa 127 

perennans 127, 130 

radiata 189 

spica-venti 127, 128, 130-131 

stolonif  era 125, 127, 129 

tennis 129 

thurberiana 127 

ventricosa 142 

verticillata 127 

virginica 127 

vulgaris 129 

Aino  millet 245 

Aira 114-116 

aquatica 47 

caerulea 50 

caespitosa 114-116 

caryophylka 116 

cristata 107 

danthonioides 116 

flexuosa -• 114 

melicoides 108 

montana 114 

obtusata 110 

praecox 116 

purpurea 76 

spicata 114 

Airochloa 107 

Alfa  grass 161 

Alfalfa : 3 

289 


290 


INDEX. 


Page. 

Alkali  grass 58 

eaccaton 15.0, 152 

Alloiatheros 187 

Alopecurus 13, 136, 137 

alpinus 137 

aristulatus 137 

californicus 137 

geniculatus 137 

aristulatus 137 

hordeiformis 137 

monspeliensis 137 

occidentalis 137 

pratensis 136, 137 

Amagris 121 

Ammophila 123 

arenaria 123, 124 

arundinacea 123 

Amphicarpon 19,  249-251 

amphicarpon 250 

floridanum 250 

purshii 250,251 

Amphilophis ; 260 

Anastrophus 223,   224 

Anatherum 263 

zizanioides 263 

Andropogon 258,  260-263 

aciculatus 270 

allioni 273 

alopecuroides 260 

ambiguus 187 

argenteus 263 

avenaceus 269 

barbinodis 263 

bicornis 260 

brevifolius 260 

ciliatus 269 

dtratus 263 

condensatus 260 

contortus 260,  273 

distachyos 260 

divaricatus 260 

drummondii 267 

elliottii ' 261 

fasdculatus 260 

furcatus 263,  264 

gryllus 270 

hirtus 260 

insularis 215 

ischaemum 260 

macrurus 260 

melanocarpus 273 

montufari 275 

muricatus —  263 


Page. 

A  ndropogon  nardus 260,  263 

nutans 260,  269 

perforatus 263 

polydactylon 189 

saccharoides 263,  265 

laguroides 263 

schoenanthus 260 

scoparius 260,  261 

sessiliflorus 260 

sorghum 267 

drummondii 267 

exiguus 267 

sudanensis 267 

tetrastachyus 260 

torreyanus 260,  263 

vaginatus 260 

virginicus 260-261,  262 

Andropogoneae 2,  20-21,  252-280 

Anemagrostis 127 

Anthaenantia 213-214 

rufa..... 214 

villosa 214 

Anthipsimus 2 

gonopodus 2 

Anthochloa 71,  73 

colusana 73 

lepidula 71 

rupestris 71 

Anthopogon 187 

lepturoides 187 

Aiithoschmidtia 83 

Anthoxanthum 201-202 

aristatum 202 

indicum 201 

odoratum 201-202 

paniculatum 201 

puellii 202 

Apera 127, 130 

spica-venti 127, 131 

Aplexia 206 

Aristida 161, 163-165 

adscensionis 163 

americana 191 

bromoides 163 

californica 163 

desmantha 163 

dichotoma 163 

fendleriana 163 


gracilis..... 163 

lanosa 163 

longiseta 163, 165 

oligantha 163,164 

purpurea 163 


INDEX. 


291 


Aristida  scabra . 

schiedeana. 

stricta 

tuberculosa. 
Arizona  fescue. . 
Arrhenatherum . 

avenaceum.. 


Page. 

163 

163 

163 

163 

31 

113 

113 

elatius 113,114 

bulbosum 113 

Arthraxon. . 266 

ciliaris 266 

cryptatherus 266 

quartinianus 266 

Arundinaria 22-24 

japonica 8 

macrosperma 22 

*      tecta 22 

Arundo .' 60,63 

arenaria 60, 123 

bambos 60 

calamagroslis 60, 121 

donax 38,  60,  62 

versicolor 60 

epigejos 60 

feslucacea 38 

karka 64 

phragmites 64 

versicolor 60 

Asperella 98 

Jiyslrix 98 

Aspris. .  „ 12, 116 

capillaris 116 

caryophyllea 116, 117 

praecox 116 

Athernotus 121 

Atheropogon 191 

apludioides 191 

Aulaxanthus 214 

dliatus 214 

rufus 214 

Aulaxia 214 

A  vena 110-113 

barbata 112,113 

calidna  (calycina) 118 

elatior 111,113 

fatua 110,  111,  112, 113 

glabrata Ill 

Jlavescens 108,  111 

fragilis Ill 

glumosa 118 

pennsylvanicua Ill 

pratensis 110 

sativa 110,  111,  113 


Avena  sibirica 110 

spicata Ill,  118, 120 

sterilis 113 

Aveneae 12-13,106-120 

Awnless  brome-grass 25 

Axonopus 523-225 

aureus 224 

compressus 224 

furcatus 225 

Bahama  grass 179 

Bamboo  tribe 22-24 

Bamboos C8+..22 

Bambos  bambos 8 

vulgaris 8 

Bamboseae 8, 22-24 

Bambusa {~$ 

Barley 98, 100, 101 

beardless 101 

rice 101 

tribe 87-106 

Barnyard  grass , 238, 240 

Bauchea 150 

karwinskyi 150 

Beach-grass 123, 124 

Beans 3 

Beckmannia 180-182 

erucaeformis 181-182 

Bennetia 150 

Bent,  carpet 129 

creeping 5, 129 

grasses 'l25-132 

Rhode  Island 5, 129 

velvet 129 

Bermuda  grass 4, 5, 178, 179 

Bigbluestem 263,264 

Billion-dollar  grass 239 

Black  grama 193 

grass 4 

sporobolus 151 

Blade 5 

Blepharidachne 6,  8,  78 

benthamiana 78 

kingii 78,  80 

Blepharoneuron 151-153 

tricholepis 151, 153 

Blue  bunch-grass 4, 31,  88 

bunch  wheat-grass 88 

grama 193, 194 

4,38,41-45 

annual 44 

Canada 44 

English 33 

Kentucky 41, 44 


292 


INDEX. 


Page. 

Bluegrass,  little 45 

malpais 44-45 

Texas 44 

joint 121,122 

stem 87 

big 263,264 

little 260,261 

Blumenbachia 266 

Botelua 191 

Bottle-brush  grass 98,  99 

Bouteloua 4, 191, 193-194 

americana 191 

aristidoides 193, 194 

barbata 191, 194 

curtipendula 191, 193, 195 

eriopoda 193 

filiformis 193 

gracilis 193, 194 

heterostega 193 

hirsuta 191, 193 

oligostachya 193 

polystachya 194 

procumbens 193, 194 

prostrata 191, 194 

racemosa 191, 193 

rothrockii 193 

simplex 191 

texana 193, 196 

triaena 193 

Brachiaria 221 

ciliatissima 221 

erucaeformis 221 

platyphylla 221,  223 

Brachyelytrum 154-156 

aristatum 156 

erectum 145, 155, 156, 157 

Brachypodium 34 

distachyon 34 

Brachystylus 107 

Briza 45 

canadensis .  ..' 34 

eragrostis 45, 46 

maxima 45 

media 45,  46 

minor 45 

Brizopyrum 58 

boreale 58 

Brome-grass 4,  24-28 

awnless 25 

downy 29 

Hungarian 25 

Schrader's 24 

smooth.  ...  25 


Page. 

Brome-grass,  wild 26 

Bromelica 69 

(section  of  Melica) 71 

Bromus 24-28 

arenarius 28 

carinatus 25 

ciliatus 25,  26 

commutatus 25 

cristatus 87 

elatior. 28 

erectus 25 

hordeaceus 28 

inermis 25 

marginatus 25 

porteri 25 

purgans 25 

racemosus 24 

rubens 28 

secalinus 24,  25,  27,  28 

sterilis 24 

tectorum 28,  29 

trinii 28 

unioloides 24 

villosus 28 

Broom  corn 267 

sedge 260,  262 

Broom-corn  millet 230 

Buchloe 197-199 

dactyloides 199 

Buffalo  grass 4, 193, 198, 199,  200 

Bulbilis : .  197-199 

dactyloides 193, 199,  200 

Bunch-grass 150 

blue 4,  31,  88 

mountain 4,  31 

Burro  grass 81,  82 

Cabrera 224 

chrysoblepharis 224 

Calamagrostis 121-123 

andina 145 

brevipilis 123, 125 

canadensis 121, 122 

langsdorfii 123 

longifolia 125 

rubescens 123 

scabra 123 

Calamovilfa 123, 125 

brevipilis 125 

curtissii 125 

gigantea 125 

longifolia 125, 126 

Calanthera 198 

dactyloides 198 


INDEX. 


293 


Page. 

Calycodon 145 

montanum 145, 147 

Campulosus 6, 16, 185 

aromaticus 185, 186 

floridanus 185 

gradlior 185 

hirsutus , 185 

Canada  bluegrass 44 

Canary  grass 203,  204 

seed 204 

Canary-grass  tribe 199-204 

Cane,  large 22 

maiden 232 

small 22,  23 

sorghum 267 

Capriola 175-179 

dactylon 178,  215 

maritima 179 

Carib  grass 221 

Carpet  grass 4,  5,  224 

Carrizo 63,  64 

Caryophyllea 116 

Catabrosa 47 

aquatica 47,  51 

Cathestecum 194-196 

erectum 196 

prostratum 195 

Cenchropsis 249 

Cenchms 247,  249 

capitatus 247 

carolinianus 249 

echinatus 247,  249 

frutescens 247,249 

granularis 280 

myosuroides 249 

pauciflorus 249 

racemosus 165,  247 

tribuloides 247,  249,  250 

Centrophorum 270 

chinense 270 

Ceratochaete 209 

Ceratochloa 24 

(section  of  Bromus) 24 

Ceresia 226 

elegans 226 

fluitans 227 

Chaboissaea 146 

ligulata 146 

Chaetaria 163 

capillaris 163 

stricta 163 

Chaetochloa 241, 243-245 

composite 2/3 


Page. 

Chaetochloa  geniculata 243 

italica 243,  244 

varietal  key  (under  Setaria) 

244-245 

lutescens 243,  244,  247 

macrostachya 243 

magna 243 

palmifolia 243 

sulcata 243 

verticillata 243 

viridis 243,  244,  247 

Chalcoelytrum 269 

Chamaeraphis 243 

Chasea 229 

Chasmanthium 60 

gratile 60 

Cheat 27 

Chess 27 

Chicken  corn 267 

Chloamnia 30 

Chlorideae 3, 16-17, 171-199 

Chloridopsis 191 

Chloris 187 

ciliata 187 

cruciata 187 

elegans 189 

falcata 185 

*  floridana 189 

gayana 189 

glauca 189 

monostachya 185 

neglecta 189 

petraea 187, 189 

polydactyla 187 

procumbens 193 

radiata 187 

verticillata 189 

virgata 189, 190 

Chloropsis 191 

blanchardiana 191 

Chlorostis 189 

Chondrosium 193 

Christ 's-tears 288 

Chrysopogon 270 

adculatus 270 

gryllus 270 

Chrysurus 68 

cynosuroides 68 

Cinna 13, 133-134 

arundinacea 133, 134 

latifolia 133, 134 

poaeformis 133 

Cinnastrum...  133 


294 


INDEX. 


Page. 

Cinnastrum  miliaceum 133 

poaeforme 133 

Citronella  grass 263 

Clomena 145 

perumana 145 

Clover 3 

Cocksfoot  grass 67 

Coelorhachis 278 

muricata 278 

Coix 287-288 

angulatus 281 

dactyloides 281,  288 

lachryma-jobi 287,  288 

Coleanthus 132-133 

subtilis 132,133 

Colobanthus 110 

Colorado  grass 232 

Corn,  Indian 383,285,286 

tribe 280-288 

Cortaderia 63 

argentea 63 

Cottea 81,  83 

pappophoroides 83, 84 

Couch-grass 87 

Crab-grasses 215,  217-218 

Creeping  bent 129 

Crested  dog's-tail  grass 67,  68 

Criterion *  98 

geniculatus. 98 

Crowfoot  grass 175*  177 

Texas 172 

Crypsinna 144 

macroura 144 

setifolia 144 

stricta 144 

Crypsis 153-154 

aculeata 154 

squarrosa 197 

Crytostachys 150 

vaginata 150 

Ctenium 185 

carolinianum 185 

Culm 5 

Curly  mesquite 4, 168, 193 

Curly-mesquite  tribe 165-170 

Curtopogon 163 

Cut-grass,  rice 206,  207 

Cymatochloa 227 

fluitans 227 

repens 227 

Cymbopogon 263 

citratus „ 263 

nardus 263 


Cynodon 175,178 

dactylon 178 

maritimus 179 

Cynosurus 67-68 

aegyptius 67, 175 

aureus 67,  68 

capillaceus 172 

coeruleus 67 

cristatus 67,  68 

cruciatus 172 

domingensis 172 

durus 67 

echinatus 67 

gradlis 169 

indicus 67 

lima 67 

monostachyos 172 

mucronatus 172 

paniceus 67 

tenellus 169 

virgatus 172 

Cyperaceae 3-4 

Cyperus  rotundus 3-4 

Dactylis 64,  67 

cynosuroides 67, 183 

glomerata 64,  66,  67 

Dactyloctenium 175 

aegyptiacum 175 

aegyptium 175, 177 

Dactylodes 281 

angulatum 281 

fasdculatum 281 

Dactylogramma 2 

cinnoides 2 

Danthonia 118, 120 

decumbens 118 

provincialis 118 

spicata 120 

unispicata 12 

Darnel 103 

DaMa 30 

elliottea 30 

Dasyochloa 74 

avenacea 74 

pulchella 74 

Davyella 71 

Deer-grass 144 

Deschampsia 114, 116 

caespitosa 116 

matthewsii 54 

Deyeuxia 121 

montana 121 

Diarina. .                                          .  51-52 


INDEX. 


295 


Page. 

Diarina  festucoides 51,  52,  53 

Diarrliena '. 51 

americana 51 

Dichanthelium  (subgemis  of  Pani- 

cum) 229 

Digitaria 215 

humifusa 218 

sanguinalis 217 

Digraphis 203 

arundinacea 203 

Dilepyrum.. 145, 156 

aristosum 145 

minutiflorum.. 145 

Dimeiostemon 260 

Dimesia 199 

Dimorphostachys 227 

Dioecious  grasses. .  8,  41,  44,  56,  63,  81, 199 

Diplachne 172 

Diplocea 76 

barbata 76 

Disarrenum  antarcticum 199 

Dissanthelium 52-54 

californicum 54 

sclerochloides 54 

supinum 54 

Distichlis 56-58 

dentata 58 

maritima 58 

multinervosa 58 

spicata 58,  59 

stricta 58 

texana 58 

Dog's-tail  grass,  crested 67,  68 

Dog-town  grass 163 

.Dropseed 151 

sand 151 

Durra 267 

Eatonia 110,  229 

purpurascens 229 

Echinochloa 238-240 

colonum 238 

crusgalli 238,  240 

edulis 238 

zelayensis 238 

walteri 240 

Echisachys 165 

Egyptian  corn 267 

Einkorn 89 

Eleusine 16, 174-175 

coracana 175 

filiformis 172 

indica 175, 176 

mrgata 172 


Elionurus.     See  Elyonurus 275 

Elymus 93-94 

arenarius 93,  94 

canadensis. 93, 94,  95 

caput-medusae 93,  94 

condensatus 94 

flavescens 94 

glaucus 94 

hystrix 98 

macounii 94 

mollis 94 

salina 94 

saundersii 94 

sibiricus „ 93 

simplex 94 

triticoides 94 

virginicus 93,  94 

Elyonurus 275 

barbiculmis 275 

tripsacoides 275,  277 

Emmer 89 

Endallax.: 203 

Endodia 206 

English  bluegrass 33 

Enneapogon 83 

desvauxii 83 

Epicampes 142-145 

berlandieri „ 144 

emersleyi 144 

ligulata 144 

macroura 145 

rigens 144 

subpatens 144 

Eragrostis 45-47 

amabilis 46,  47 

caroliniana 47 

cilianensis 47, 48 

ciliaris 47,  50 

eragrostis 46 

hypnoides 46,  47 

major 47 

megastachya 47 

oxylepis 47 

pectinacea 46,  47,  49 

plumosa 47 

secundiflora 47 

sessilispica. 46 

Eremochloa 78 

Eremochloe 78 

bigelovii 78 

Tcingii 78 

Erianthus 255,  258 

brevibarbis. .  258 


296 


INDEX. 


Page. 

Erianthus  contortus 258 

divaricatus 258 

ravennae 258 

eaccharoides 258,  259 

strictus 258 

Eriochloa 219-221 

acuminata 221 

distachya 220 

polystachya 220,  221 

punctata 220,  221,  222 

subglabra 221 

Eriocoma 156 

cuspidata 156 

Erioneuron 74,  76 

Erochloe 46 

Erosion 46 

Esparto  grass 5 

Euchlaena 281-283 

mexicana 281,  283,  284 

Eulalia 255,256 

japonica 255 

Eustachys 189 

petraeus 189 

Eutriana 193 

bromoides 193 

curtipendula 193 

Fartis 209 

Fendlera 158 

rhynchelytroides 158 

Fescue,  Arizona 4,  31 

grasses 28-34 

hard 31 

meadow 31,  33 

red 31,32 

sheep's 31 

tall 32 

tribe 24-86 

Festuca 28-34 

arizonica. 31 

borealis 38 

bromoides 30 

californica 31 

capillata 31 

confinis 30,  31 

cristate 28 

decumbens 28,  74, 118 

diandra 51 

duriuscula 31 

elatior 28,  31,  33 

elmeri 31 

fasdcularis 172 

fluitans 28,  34 

heterophylla 31 


Page. 

Festuca  idahoensis 31 

ingrata 31 

myuros 28,  30 

obtusa 31 

octoflora 30 

ovina 28,  31 

rubra 31,  32 

sciurea 30 

subulata 31 

subuliflora 31 

tenella 30 

unioloides 24 

viridula .' 31 

Festucaria 34 

Festuceae 8-10,  24-28, 196 

Feterita 267 

Fiber  grasses 4,  5 

Fiorin 129 

Flat- stem 44 

Flexularia 2 

compressa 2 

Floret 5 

Fluminea 38 

arundinacea. 38 

festucacea 38,  40 

Foragegrasses 3,  4 

Forasaccus 24 

Fountaingrass 247 

Fowl  meadow  grass 44 

Foxtail  grass 96 

green 243 

meadow 136 

millet 243 

yellow 243,244 

Fussia 116 

capillaris 116 

caryophyllea 116 

praecox 116 

Galleta  grass 169, 170 

Gama  grass 281,  282 

Gardener's  garters 203 

Gastridium 141-142 

australe 141 

lendigerum 142 

ventricosum 142 

German  millet 245 

Giant  reed 60,  62 

Ginannia 117 

mollis 117 

pubescens 117 

Glyceria 34 

Glume 5 

Gnomonia 30 


INDEX. 


297 


Page. 

Golden-top 08,  G9 

Golden-wonder  millet 245 

Goose-grass 175, 176 

Grains 4 

Grama,  black 193 

blue 193,194 

grasses 4, 191, 193-194 

side-oats 193, 195 

six-weeks 194 

tribe 171-199 

Gramineae. 3 

Grapevine  mesquite 232,  235 

Graphephormn 108 

festucaceum 38 

flexuosum 54 

Grass,  definition 3 

Grasses  distinguished  from  sedges.          3 

Green  foxtail 243 

Greenia 135 

arJcansana 135 

Guinea  grass 230 

Gymnopogon 185-187 

ambiguus 187, 188 

brevifolius 187 

chapmanianus 187 

•f  oliosus 187 

racemosus 187 

Gymnostichum 98 

hystrix 98 

Gymnothrix 246 

thourii 246 

Gynerium 63 

argenteum 63 

saccharoides 63 

sagittatum 63 

Hackelochloa 278,  280 

granularis 280 

Hair-grass,  tufted 116 

Hare's-tail  grass 143 

Harpechloa 185 

Hay. 4 

grain 4, 113 

wild 4,  89, 121 

Heleochloa 154 

alopecuroides 154 

schoenoides 154, 155 

Helopus 220 

pilosus 220 

Hemarthria 278 

compressa 278 

undnata 278 

Herd's-grass 129 

Hesperochloa 30 

(subgenua  of  Festuca) 30, 31 


Tage. 

Heteropogon 273 

contortus 273,  274 

glaber 273 

hirtus 273 

melanocarpus 273 

Heterosteca 193 

jundfolia 193 

Ilexarrhena 168 

cenchroides 168 

Ilierochloe 199 

antarctica 199 

borealis 199 

odorata. 199 

Hilaria 4, 167-169 

belangeri 168, 193 

cenchroides 167, 168 

jamesii 169, 170 

mutica 169 

rigida 169 

Himalaya  fairy  grass 255 

Hog  millet 230 

Holcus 20, 116, 117,  266-269 

exiguus 267 

fragrans 199 

halepensis 266,  267,  268 

lanatus 117, 118,  266 

laxus 266 

odoratus 266 

saccharatus 266 

sorghum 266,  267 

sorghum  drummondii 267 

exiguus 267 

sudanensis •. .       267 

spicatus 246 

striatus 237,  266 

Holy  grass 199 

Homalocenchrus 204-206 

monandrus 206 

oryzoides 206,  207 

virginicus 206 

Hordeae 11-12,  87-106 

Hordeum 98-101 

distichon 98,  99 

gussoneanum 101 

hexastichon 98,  99 

ischnatherum 101 

jubatum 98, 101 

murinum 98, 101 

nodosum 101, 102 

pusillum 101 

spontaneum 101 

vulgare 98,100 

trifurcatum 101 

zeocriton 98, 101 


298 


INDEX. 


Hungarian  brome-grass. 


Page. 

25 

245 

Hydrochloa 211 

carolinensis 211,  213 

fluitans 211 

Hydropyrum 209 

esculentum 209 

Hymenothecium 169 

quinquesetum 169 

tenellum 169 

trisetum 169 

unisetum 169 

Hystrix 96-98 

californica 98 

hystrix 98 

patula 98,  99 

Imperata 252 

arundinacea 252 

brasiliensis 252 

hookeri 252,  254 

Indian  corn 283,  285,  286 

grass 270,271 

mountain  rice 158 

reed 270 

rice 3,209 

Indian-rice  tribe 206-211 

Injurious  grasses 28, 

96, 101, 103, 161, 163,  269,  273 

Ixophorus 241 

Japanese  lawn-grass 166 

Jerusalem  corn 267 

Job's-tears 287,  288 

Johnson^grass 4,  267,  268,  269 

Juncaceae 3 

Juncus  gerardi 4 

June  grass 44 

Kafir 4,267 

corn 267 

Kaoliang 267 

Kentucky  bluegrass 41 

Khas-khas 263 

Khus-khus 263 

Koeleria 12, 106-107 

cristata 107, 108 

longifolia ; 107 

gracilis 107 

pennsylvanica 110 

phleoides 28, 107 

•     tuberosa 107 

villosa 107 

Korean  lawn  grass 166 

Korycarpus 52 

arundinaceus ...  52 


Page. 

Kryp-hwen. 127 

Krypven 127 

Kursk  millet 245 

Lagurus 142 

cylindricus 252 

ovatus 142, 143 

Lamarckia 68 

aurea 68 

Lappago 165 

Lappagopsis 224 

bijuga 224 

Lasiacis 232,  234-236 

divaricata 236 

Lawn  grass 4,  5, 44, 129,  225 

Japanese 166 

Korean 166 

Leersia 204, 205 

hexandra 205 

lenticularis 206 

monandra 205 

oryzoides 205 

virgata 206 

virginica 206 

Lemma 5 

Lemon  grass 263 

Lepiurus 106 

Leptocercus 105 

Leptochloa 16, 171-172 

domingensis 172 

dubia 172 

fascicularis 172 

filiformis 172,173 

floribunda 172 

spicata 174 

virgata 172 

Leptoloma 218 

cognatum 218, 219 

Lepturus 103, 105 

bolanderi 91 

cylindrica 105 

filiformis 106 

paniculatus 180 

repens 105 

Lesourdia 81 

karwinskyana 81 

multiflora 81 

Ligule 5 

Limnetis 183 

cynosuroides 183 

juncea 183 

polystachya 183 

pungens 183 

Limnodea 13,134-136 


INDEX. 


299 


Page. 

Limnodea  arkansana 135 

pilosa 136 

Little  bluestem 260,  261 

Lodicularia 278 

fasdculata 278 

Lodicules 5 

Lolium 101, 103 

italicum 103 

multiflorum 103, 104 

perenne 103 

temnlentiim 103 

Lophochlaena 36 

californica 36 

Love-grass 49 

Luziola 209,  211 

alabamensis 211 

peruviana 211,  212 

Lycunis 13, 139 

phalaroides 139 

phleoides 139 

Lygeum  spartum 5 

Macronax 22 

Maiden  cane 232 

Maize 283 

Malojilla 221,  230 

Malpais  bluegrass 44-45 

Manienie 179 

Manila  grass 166, 167 

Manisuris 278,  280 

cylindrica 278,  279 

fasciculata 278 

granularis 280 

myuros 278 

rugosa 278 

tessellata 278 

Manna  grass 35 

Marram  grass 123 

Marsh  grass 184 

Matrella 166 

Maydeae 22 

Mays 283 

zea 283 

Mayzea 283 

cerealis 283 

Meadow  fescue 4,  31,  33 

foxtail 136-137 

grasses 4 

Melic  grasses 71 

Melica 68-71 

altissima 69 

aristata 71,  72 

bella..  71 


Page. 

Melica  bromoides 69 

ciliata 69 

geyeri 69,  71 

imperfecta. 8,  71 

mutica 69,  70 

nitens 69,  71 

nutans 69 

purpurascens 71 

smithii 71 

spectabilis 71 

torreyana 8 

Melinideae 18,  212-213 

Melinis 212-213 

miniitiflora 212-213 

Melinum 209 

palustre. 209 

Merathrepta 118, 120 

Merisachne 76 

drummondii 76 

Mesquite,  grapevine 232,  235 

Mibora  minima 133 

Miegia . .        22 

Milium 156 

amphicarpon 249 

dmidnum 224 

coerulescens 156, 158 

compressum 223 

confertum 156 

digitatum 224 

effusum *. 156,158 

lendigerum 141, 142 

paniceum 224 

paradoxum 158 

punctatum 220 

ramosum 220 

Millet 243 

broom-corn 230 

foxtail 243 

grass 158 

-   hog 230 

pearl 246 

proso 230 

Texfes 232 

tribe 213-251 

Milo  maize 267 

Miphragtes 64 

Miscanthus 252,  254,  255 

capensis 254,  255  . 

japonicus 254 

luzonensis 254 

nepalensis 255 

purpurascens 254 


300 


INDEX. 


Page. 

Miscanthus  sinensis. ... 254,  255,  256 

gracillinms 255 

variegatus 255 

zebrinus 255 

Molasses  grass 212-213 

Molasses-grass  tribe 212-213 

Molinia 47,  50 

caemlea 50,  52 

varia 50 

Monanthera 185 

Monanthochloe 56 

littoralis 56,  57 

Monerma 103, 105, 106 

monandra 105 

Monocera 185 

Monoecious  grasses 22, 199,  206, 

209,  211,  280,  281,  283,  286,  287 

Monroa 197 

Moulinsia 163 

Mountain  bunch-grass 31 

rice,  Indian 158 

Muhlenbergia 145-148 

andina 145 

capillaris 145, 147, 148 

depauperata 146 

emersleyi 145 

erecta 155 

expansa 145 

gradlis 147 

ligulata 146 

mexicana 146 

microsperma 146 

montana 145, 147 

peruviana 145 

repens 146 

schreberi 145, 147 

squarrosa 146 

trifida 147 

vaseyana 145 

wrightii : 147 

Munroa 197 

benthamiana 78 

mendocina 197 

squarrosa 78, 197, 198 

Mutton  grass 41,  45 

Napier  grass 247 

Nasella 158 

Natal  grass 4,  241,  242 

Nazia 165 

aliena 165 

racemosa 165 

Nazieae 3,15-16, 165-170 

Needle  grasses 161, 163-165 


Page. 

Needle-and-thread  grass 161 

Neeragrostis 46 

hypnoides 46 

Neostapfia 71 

Nevroctola 60 

Nevroloma 34 

Nimble  Will 147 

Nothoholcus 118 

Notholcus 116-118 

lanatus 118, 119 

mollis 118 

Notonema 127 

Nut-grass 3-4 

Oat 110,  111,  113 

Algerian 113 

animated 113 

grain  hay 4 

red 113 

tribe 106-120 

wild Ill,  112 

Oat-grass,  tall 113, 114 

wild 120 

Oedipachne 220 

punctata 220 

Oil  grasses 263 

Old-witch  grass 232,233 

Olyra 252 

latifolia 252,  253 

Onion  grass 71 

Oplismenus 237-238 

africanus 238 

setarius 238,  239 

zelayensis 238 

Orchard  grass 4,  66,  67 

Orcuttia 78,  80 

californica 80 

greenei 80 

Ornamental  grasses 4,  5,  60 

Ortachne 163 

Orthopogon 238 

aemulus 238 

compositus 238 

flaccidus 238 

imbedllis 238 

Oryza 2,  204 

sativa 204,  205 

Oryzeae 2-3, 18,  204-206 

Oryzopsis 156,158 

asperifolia 156 

hymenoides 156, 158 

Osterdamia 15, 165-166 

japonica 166 

matrella 166, 167 


INDEX. 


301 


Page. 

Osterdamia  tenuifolia 166 

Oxyanthe 64 

Oxydenia 172 

attenuate, 172 

Palea 5 

Palm-grass 243 

Pampas    grass 63 

hardy 258 

Paneion 41 

Panicastrella 247 

Panicatae  (subfamily) 7-8 

Paniceae 18-20,  213-252 

Panicularia 34-36 

canadensis 34 

fluitans 34 

grandis 36 

nervata 34,  35,  36 

pauciflora 36 

Panicum 227-232 

autumnale : 218 

barbinode 229 

bulbosum 231-232 

capillarc 232,  233 

dliatissimum 221 

clandestiiium 229 

cognatum 218 

compositum 238 

crusgalli 238 

dactylon 178,  215 

dichotomiflorum 232 

dichotomum 229,  230 

dimidiatum 218,  278 

dissectum 225 

divaricatum 229,236 

erucaeforme 221 

frumentaceum 238 

geminatum 232,  234 

gibbum 237 

glabrum 218 

glaucum 243,  247 

hemitomon 232 

hians 229 

lachnanihum 215 

lanatum 215 

leucophaeum 215 

maximum 230 

miliaceum 204,  229,  230 

molle 230 

monostachyum 227 

obtusum 232,  235 

plicatum 243 

sanguinale 215 

sonorum...  232 


Tage. 

Panicum  sulcatum 243 

texanum 232 

virgatum 229,  231 

vinde 241 

Pappophorum 88,  85-86 

alopecuroideum 83 

bicolor 83 

gracile 83 

nigricans 83 

pallidum 83 

purpurascens 83 

vaginatum 83,  85 

wrightii 83,  86 

Para  grass 221,  229,  230 

Paspalum 18,225-227 

bifidum 227 

ciliatifolium 227 

dilatatum 227 

dimidiatum 225 

distichum 226,227 

laeve 227,  228 

notatum 227 

paniculatum 226 

platyculmum 224 

pulchellum 227 

repens 227 

virgatum 226 

Pasture  grasses 4, 44 

Paurochaetium  (subgenusof  Pani- 
cum)        229 

Pearl  millet 246 

Peas 3 

Penicillaria 246 

spicata 246 

Pennisetum 245-247 

americanum 246 

cenchroides.t 245 

glaucum 246,  247 

longistylum 247 

orientale 245 

purpureum 247 

ruppelii 247 

setosum 245,  247, 248 

typhoideum 245,  246,  247 

villosum 247 

violaceum 245 

Pentameris 118, 120 

thuarii 120 

Phalarideae 6, 17, 199-204 

Phalaris 202-204 

arundinacea 203 

picta 203 

canariensis 202-203,  204 


302 


INDEX. 


Page. 

Phalaris  caroliniana 204 

erucaeformis 181,  203 

oryzoides 203,  205 

pjikoides 203 

villosa 214 

Phanopyrum 229 

gymnocarpon 229 

Pharus 211-212 

latifolius 211 

Phippsia 132 

algida 132 

Phleum 140-141 

alpinum 140 

arenarium 140 

bellardi 141 

graecum 141 

pratense 140, 141 

schoenoides 140, 153 

Pholiurus 105-106 

incurvatus 106 

Phragmites 64 

communis 64,  65 

phragmites 64 

Phyllostachys 8 

Pili 273 

Pine-grass 4,123 

Piptatherum 156 

coerulescens 156, 158 

punctatum 156, 158 

Piptochaetium 158 

Pleopogon 139 

setosum 139 

Pleuraphis 168 

jamesii 168 

Pleuropogon -36 

californicus 36,  37 

refractus 36 

sabinii 36 

Plume-grass 258,  259 

Poa 38,  41-45 

amabilis 41 

annua 41,  44 

aquatica 34, 41 

arachnifera 41,  44 

bolanderi 41 

caerulescens 74 

capillaris 41 

chinensis -. 41 

compressa 41, 44 

distans 38 

douglasii 41 

eragroslis 41,  46 

fendleriana 41,  45 


Page. 

Poa  flava 41,  76 

howellii 41 

kingii 30 

macrantha 41 

malabarica 41 

nemoralis 128 

nevadensis 41 

palustris 44 

pilosa 41 

pratensis 41, 43 

quinquefida 74 

rigida 34 

sand!  >ergii 41, 45 

scabrella 41, 42, 44 

serotina 44 

tenella 41 

triflora 44 

trivialis 44 

weigeltiana 46 

Poaceae 3, 5-6 

Poatae  (subfamily) 6-7 

Pod  corn 287 

Podagrostis 127 

(section  of  Agrostis) 127 

Podopogon 160 

Podosemum 145 

capillaris 145 

Poisonous  grasses 36, 161,  269 

Pollinia 270 

gryllus 270 

Polyanihrix 96 

Polyodon 193 

distichum 193 

Polypogon 13, 137-139 

littoralis 138 

lutosus 138 

maritimus 138 

monspeliensis 138 

Polyrhaphis 83 

(section  of  Pappophorum) 83 

Poranthera 269 

Porcupine  grass 160 

Poverty  grass 120, 165 

Prairie  hay 3 

Proso  millet 230 

Psamma 123 

littoralis 123 

Ptychophyllum  (section  of  Chae- 

tochloa) 243 

Puccinellia 36,  38 

airoides 38 

distans 38 

festucaeformis...  38 


INDEX. 


303 


Page. 

Puccinellia  gussonii 38 

maritima 38 

nuttalliana 38,  39 

Purple-top 77 

Quack-grass 87,88 

Quaking  grass 45,  46 

Rabdockloa 172 

domingensis 172 

Rachilla 5 

Range  grasses. 4 

Rarum 249 

Ravenna  grass 258 

Reana  luxurians 283 

Reboulca 110 

gracilis 110 

Red.  sprangle-top 173 

Redfieldia 54-56 

flcxuosa 54,  55 

Redtop 4, 128, 129 

Reed,  giant 60,  62,  63 

Reed-grass,  wood 134 

Reeds 63,64,65 

Reimaria 225 

acuta 225,  226 

Candida 225,  226-227 

elegans 226 

Reimarochloa 18,  225 

oligostachya 225,  226 

Rhaphis 270,272-273 

pauciflora 270,  272 

trivialis 270 

Rhapis. 270 

Rhode  Island  bent 129 

Rhodes  grass 189 

Rhombolytrum 74 

rhomboidea 74 

Ribbon  grass 203 

Rice 204,205 

cut-grass 206, 207 

Indian 209 

tribe 204-206 

wild 209,210 

Rottboellia 278 

compressa 278 

dimidiata 218 

fasciculata 278 

incurvata 106 

pannonica 106 

repens 105 

Rushes  distinguished  from  grasses .       3-4 

Rye 91,92 

wild..  95 


Page. 

Rye-grass 193 

Australian. 103 

English io3 

Italian 103,104 

perennial 193 

Rytilix 278,  280 

glandulosa 280 

granularis 280 

Saccaton 151 

alkali 150, 152 

Saccharine  sorghums 267 

Saccharum 255 

floridulum 255 

officinarum 255,  257 

spicatum 255 

Sacciolepis 236-237 

striata 237 

Saint  Augustine  grass 5,  219,  220 

Salt-grass 58,  59 

Sand-binding  grasses 5, 123, 125 

Sand  bur 249 

Savastana 199 

hirta 199 

Schedonnardus 179-180 

paniculatus 180, 181 

texanus 180 

Schedonorus 28 

Schellingia 169 

tenera 169 

Schizachyrium 260 

condensation 260 

Schleropelta 168 

stolonifera 168 

Schmidtia 132 

subtilis 132 

Schoenus  aculeatus 153 

Schrader's  brome-grass 24 

Sclerachne 135 

arlcansana 135 

pilosa 135 

Selena  elata 209 

Scleropoa 34 

rigida '. 34 

Scleropogon 81 

brevifolius 81,  82 

Scolochloa 38 

festucacea 38 

Scribneria 91 

bolanderi 91,  93 

Sea  marram 123 

Seaside  oats 60 

Secale 91 


304 


INDEX. 


Page. 

Secale  cereale 91-92 

creticum 91 

montanum 91 

orientate 91 

wllosum 91 

Sedge  distinguished  from  grasses.      3-4 

Seneca  grass 199 

Sericrostis 145 

Serrafalwis 24 

Sesleria  dactyloides 198, 199 

Setaria 241,  243-245 

glauca 243 

italica 243-245 

varietal  key 244-245 

wridis 241 

Shallu 267 

Sheath 5 

Sheep's  fescue 31 

Short-grass 193 

country 199 

Siberian  millet 245 

Side-oats  grama 193, 195 

Sieglingia 74 

albescens 74 

decumbens 74, 118 

Sitanion 94,  96 

elymoidcs 96 

hystrix 96,  97 

jubatum 96 

planifolium 96 

Six-weeks  grama 194 

Sleepy  grass 161 

Slough-grass 181-182 

Smut-grass 149, 150 

Soil  binders 4,  5 

Soiling  grasses 4 

Sorghastrum 20,  269-270 

avenaceum 269 

elliottii 270 

nutans 269,  270,  271 

secundum 270 

Sorghum 266-269 

tribe 252-280 

vulgare 266,  267 

Sorgo 267 

Sorgum 266 

Sour-grass 215,  216 

Spartina 182-185 

alterniflora 183 

glabra 183 

pilosa'. 183 

bakeri 183, 185 

cynosuroid.es = 183 


Page. 

Spartina  foliosa 183 

gracilis 183 

juncea 183 

maritima 183 

michauxiana 183, 184 

patens 183, 185 

juncea 185 

schreberi 183 

spartinae 183 

stricta 183 

tenacissima 5 

Spear-grasses 158-161 

Sphenopholis 12, 109, 110 

obtusata 110-111 

lobata 110 

pallens 110 

palustris ' 109 

Spikelet : 5 

Spirochloe 180 

Spirotheros 273 

Sporobolus 149-151 

airoides 4, 150, 152 

berteroanus 149, 150 

black 151 

cryptandrus 150, 151 

elongatus 150 

gracilis 150 

indicus 150 

interruptus 151 

pulchellus 150 

vaginaeflorus 150 

virginicus 150 

wrightii 150 

Sprangle-top 172 

red 173 

Squirreltail  grass 96 

Stapfia 71 

colusana 71 

Stegosia 278 

cochinchinensis 278 

Stcinchisma 229 

Stelephuras 140 

Stenotaphrum 218-219 

americanum 219 

glabrum 218 

secundatum 219,  220 

Stink-grass 48 

Stipa 158-161 

avenacea 159, 160, 161 

barbata 160 

calamagrostis 127 

capillaris 145 

comata 161 


INDEX. 


305 


Page. 

Stipa  juncea 159 

lettermani 161 

melanocarpa 273 

minor 161 

neo-mexicana 161 

pennata 159 

sericca 145 

epartea 160,161 

speciosa 161 

tenuissima 161, 162 

vaseyi. 161 

viridula 161 

Streptachne 163 

pilosa 163 

stipoidcs. 163 

(section  of  Aristida) 163 

Sudan  grass 267 

Sugar  cane 255,  257 

Sugar-producing  grasses 4,  5 

Sweet  vernal  grass 201,  202 

Switch-grass 231 

Syntherisma 215,  217-218 

filiformis 218 

ischaemum 218 

praecox 215 

sanguinalis 215, 217 

serotina 215 

villosa 215 

Tabosa  grass 169 

Tall  oat-grass 113, 114 

Tares  (of  Scripture) 103,  209 

Teosinte '...  283,  284 

Terrcllia 93 

Texas  bluegrass 44 

crowfoot 172 

millet 232 

Textile  grasses 4,  5 

Thurberia 135 

Tickle  grass 130 

Timothy 4,140,141 

mountain 140-141 

tribe 121-165 

Toothache  grass 185, 186 

Torresia 199,  201 

alpina 201 

macrophylla 201 

odorata 199,  201 

utriculata 199 

Tosagris 145 

agrostidea 145 

Trachynotia 183 

cynosuroides 183 

97769°— 19— Bull.  772 20 


Page. 

Trachynotia  juncea 183 

polystachya 183 

Trachypogon 20-275 

montufari 275,  276 

Tragus. 165 

Triaena 193 

racemosa 193 

Triaihera 191 

Tribes,  sequence 2 

Trichachne 215 

insularis 215 

Trichloris. 189, 191 

blanchardiana 191 

fasciculata 190* 

mendocina 191, 192 

pluriflora 190 

Trichochloa 145, 

expansa 145 

purpurea 145 

Trichodium 127 

decumbens 127 

laxiflorum 127 

Tricholaena 241 

micrantha 241 

rosea 241,242 

Trichoon 64 

Tricuspis 74 

caroliniana 74 

novaeboracensis 74 

Tridens 74 

quinquefida 74 

Triodia 73-76 

albescens '. .  74,  76 

avenacea 74,  75 

drummondii 76 

elongata 76 

flava 74,  76,  77 

mutica 76 

nealleyi 75 

pilosa 75 

pulchella 74, 75,  76 

pungens 74 

stricta 76 

trinerviglumis 74 

Triplasis 76,  78 

americana 76,  IS 

intermedia 78 

purpurea 78,  79 

Tripogon 172-174 

bromoides 174 

spicatus 174 

Tripsaceae 2,  22,  280-28& 


306 


IXDEX. 


Page. 

Tripsacum, 280-281 

dactyloides 281  282 

fasciculatum 281 

fioridanum 281 

hermaphroditum 281 

lemmoni 281 

Trisetum 107-109 

canescens 108 

cernuum 108 

hallii 109 

interruptum 109 

melicoideum ..       108 

pennsylvanicum 109 

pratense 108 

spicatum 108, 109 

wolfii 108 

Trixiola 60 

paniculata 60 

Triticum 89 

aestivum 89,  90 

caninum 89 

dicoccoides 89 

dicoccum.... 89 

hybemum . . 89 

monoccocum 89 

repens 89 

sativum 89 

spelta 89 

turgidum 89 

•vulgare 89 

Trixostis 163 

Tufted  hair-grass 116 

Tunis  grass 267 

Turkish  millet 245 

Type  species,  definition 2 

Typhoides 203 

arundinacea 203 

Uniola 6,  8,  58-60 

gradlis 60 

latifolia 60,  61 

laxa 60 

maritima 60 

palmeri 60 

paniculata 59,  60 

spicata 58,  59 

Urachnc 158 

coerulescens 158 

parviflora 158 

xircscens 158 

Uralepis 74,  76 

aristulala 76 

pilosa 74 

purpurea 76 


Page. 

Umlepsis '. 74,  76 

Uva  grass 63 

Valota 214,  215 

hitchcockii 215 

insularis 215,  21G 

saccharata 215 

Vanilla  grass 199,  201 

Vaseya 145 

comata 145 

Velvet  bent 129 

grass 118, 119 

Vernal  grass,  sweet 201,  202 

Vetch 3 

Vetiver 263 

Vctiveria  zizanioides 263 

Vilfa 127 

tricholepis 151 

Vulpia 28 

myuros 28 

(subgenus  of  Festuca) 30 

Wasatchia 30 

kingii 30 

Water  grass 227 

Weingaertneria  canescens 116 

Western  wheat-grass 87 

Wheat 89,90 

club 89 

durum 89 

grain  hay 4 

Wheat-grass 4,87 

slender 87 

western 87 

Wildest-grass 120 

oats ^ 111,112 

rice 200, 210 

rye 95 

Willkommia 179 

annua 179 

sarmentosa 179 

texana 179, 180 

Windmill  grass 189 

Windsoria 74 

ambigua 74 

poaeformis 74 

Wire-grass 44,  179 

Witch-grass,  old 232,  233 

Wolftail 139 

Wood  reed-grass 134 

Woolly  foot 193 

Xiphagrostis 255 

floridula 255 

japonica 255 

Yard-grass 175 


INDEX. 


307 


Page. 

Yellow  foxtail 343,244 

Zea 22,  283,  287 

mays 283,  285,  286 

japonica 287 

tunicata 287 

Zeia 89 

Zeocriton 98 

Zerna 24 

Zizania 3,  206, 209 

aquatica • 209 

fluitans...  211 


Page. 

Zizania  latifolia 209 

microstachya 206 

palustris 206,  209,  210 

terrestris 209 

Zizanieae 3, 18,  206-211 

Zizanion 209 

Zizaniopsis 206 

miliacea 206,  208 

Zoysia 165-166 

pungens 166 

Zoysieae 3, 15, 196 


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